diff --git a/src/pkgmgr/__init__.py b/src/pkgmgr/__init__.py
index 427934d..9b06509 100644
--- a/src/pkgmgr/__init__.py
+++ b/src/pkgmgr/__init__.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 Top-level pkgmgr package.
 
diff --git a/src/pkgmgr/actions/archive/workflow.py b/src/pkgmgr/actions/archive/workflow.py
index 0c1b72b..8616523 100644
--- a/src/pkgmgr/actions/archive/workflow.py
+++ b/src/pkgmgr/actions/archive/workflow.py
@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import contextlib
 from dataclasses import dataclass
 from pathlib import Path
 
diff --git a/src/pkgmgr/actions/branch/close_branch.py b/src/pkgmgr/actions/branch/close_branch.py
index d9b8b39..3ed8197 100644
--- a/src/pkgmgr/actions/branch/close_branch.py
+++ b/src/pkgmgr/actions/branch/close_branch.py
@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-from typing import Optional
-
 from pkgmgr.core.git.commands import (
     GitDeleteRemoteBranchError,
     checkout,
@@ -17,7 +15,7 @@ from pkgmgr.core.git.queries import get_current_branch, resolve_base_branch
 
 
 def close_branch(
-    name: Optional[str],
+    name: str | None,
     base_branch: str = "main",
     fallback_base: str = "master",
     cwd: str = ".",
diff --git a/src/pkgmgr/actions/branch/drop_branch.py b/src/pkgmgr/actions/branch/drop_branch.py
index 9010233..e75fa00 100644
--- a/src/pkgmgr/actions/branch/drop_branch.py
+++ b/src/pkgmgr/actions/branch/drop_branch.py
@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-from typing import Optional
-
 from pkgmgr.core.git.commands import (
     GitDeleteRemoteBranchError,
     delete_local_branch,
@@ -12,7 +10,7 @@ from pkgmgr.core.git.queries import get_current_branch, resolve_base_branch
 
 
 def drop_branch(
-    name: Optional[str],
+    name: str | None,
     base_branch: str = "main",
     fallback_base: str = "master",
     cwd: str = ".",
diff --git a/src/pkgmgr/actions/branch/open_branch.py b/src/pkgmgr/actions/branch/open_branch.py
index 1a13fa1..5758ab4 100644
--- a/src/pkgmgr/actions/branch/open_branch.py
+++ b/src/pkgmgr/actions/branch/open_branch.py
@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-from typing import Optional
-
 from pkgmgr.core.git.commands import (
     checkout,
     create_branch,
@@ -13,7 +11,7 @@ from pkgmgr.core.git.queries import resolve_base_branch
 
 
 def open_branch(
-    name: Optional[str],
+    name: str | None,
     base_branch: str = "main",
     fallback_base: str = "master",
     cwd: str = ".",
diff --git a/src/pkgmgr/actions/changelog/__init__.py b/src/pkgmgr/actions/changelog/__init__.py
index 88cb2a5..5d0f868 100644
--- a/src/pkgmgr/actions/changelog/__init__.py
+++ b/src/pkgmgr/actions/changelog/__init__.py
@@ -1,13 +1,9 @@
-#!/usr/bin/env python3
-
 """
 Helpers to generate changelog information from Git history.
 """
 
 from __future__ import annotations
 
-from typing import Optional
-
 from pkgmgr.core.git.queries import (
     GitChangelogQueryError,
     get_changelog,
@@ -16,8 +12,8 @@ from pkgmgr.core.git.queries import (
 
 def generate_changelog(
     cwd: str,
-    from_ref: Optional[str] = None,
-    to_ref: Optional[str] = None,
+    from_ref: str | None = None,
+    to_ref: str | None = None,
     include_merges: bool = False,
 ) -> str:
     """
diff --git a/src/pkgmgr/actions/code_scanning/__init__.py b/src/pkgmgr/actions/code_scanning/__init__.py
index c2cdc0c..ed24c1c 100644
--- a/src/pkgmgr/actions/code_scanning/__init__.py
+++ b/src/pkgmgr/actions/code_scanning/__init__.py
@@ -27,14 +27,14 @@ class CodeScanningResult:
     repo: str
     output_dir: str
     alert_count: int
-    files: List[str] = field(default_factory=list)
+    files: list[str] = field(default_factory=list)
 
 
-def _gh(args: List[str]) -> subprocess.CompletedProcess[str]:
-    return subprocess.run(["gh", *args], capture_output=True, text=True)
+def _gh(args: list[str]) -> subprocess.CompletedProcess[str]:
+    return subprocess.run(["gh", *args], capture_output=True, text=True, check=False)
 
 
-def _resolve_repo(repo: Optional[str]) -> str:
+def _resolve_repo(repo: str | None) -> str:
     if repo:
         return repo
     proc = _gh(["repo", "view", "--json", "nameWithOwner", "-q", ".nameWithOwner"])
@@ -48,7 +48,7 @@ def _resolve_repo(repo: Optional[str]) -> str:
     return name
 
 
-def _fetch_json(endpoint: str, params: Optional[List[str]] = None) -> Any:
+def _fetch_json(endpoint: str, params: list[str] | None = None) -> Any:
     args = ["api", endpoint, "--paginate"]
     for param in params or []:
         args += ["-f", param]
@@ -74,7 +74,7 @@ def _alert_row(alert: dict) -> str:
     return f"- [{severity}] {rule_id} — {path}:{line} ({state})\n  {message}"
 
 
-def _build_summary(repo: str, generated_at: str, alerts: List[dict]) -> str:
+def _build_summary(repo: str, generated_at: str, alerts: list[dict]) -> str:
     by_severity: Counter = Counter()
     by_state: Counter = Counter()
     by_rule: Counter = Counter()
@@ -112,9 +112,9 @@ def _build_summary(repo: str, generated_at: str, alerts: List[dict]) -> str:
 
 
 def download_code_scanning(
-    repo: Optional[str] = None,
-    output_dir: Optional[str] = None,
-    state: Optional[str] = None,
+    repo: str | None = None,
+    output_dir: str | None = None,
+    state: str | None = None,
 ) -> CodeScanningResult:
     if not shutil.which("gh"):
         raise CodeScanningError("the GitHub CLI 'gh' is not installed or not on PATH")
diff --git a/src/pkgmgr/actions/config/add.py b/src/pkgmgr/actions/config/add.py
index f4962ae..b4d216b 100644
--- a/src/pkgmgr/actions/config/add.py
+++ b/src/pkgmgr/actions/config/add.py
@@ -30,7 +30,7 @@ def interactive_add(config, USER_CONFIG_PATH: str):
     confirm = input("Add this entry to user config? (y/N): ").strip().lower()
     if confirm == "y":
         if os.path.exists(USER_CONFIG_PATH):
-            with open(USER_CONFIG_PATH, "r") as f:
+            with open(USER_CONFIG_PATH) as f:
                 user_config = yaml.safe_load(f) or {}
         else:
             user_config = {"repositories": []}
diff --git a/src/pkgmgr/actions/config/init.py b/src/pkgmgr/actions/config/init.py
index 2c6a158..e19a1e8 100644
--- a/src/pkgmgr/actions/config/init.py
+++ b/src/pkgmgr/actions/config/init.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 Initialize user configuration by scanning the repositories base directory.
 
@@ -22,7 +20,7 @@ For each discovered repository, the function:
 from __future__ import annotations
 
 import os
-from typing import Any, Dict
+from typing import Any
 
 from pkgmgr.core.command.alias import generate_alias
 from pkgmgr.core.config.save import save_user_config
@@ -30,8 +28,8 @@ from pkgmgr.core.git.queries import get_latest_commit
 
 
 def config_init(
-    user_config: Dict[str, Any],
-    defaults_config: Dict[str, Any],
+    user_config: dict[str, Any],
+    defaults_config: dict[str, Any],
     bin_dir: str,
     user_config_path: str,
 ) -> None:
@@ -128,7 +126,7 @@ def config_init(
                         "[WARN]       Could not read commit (not a git repo or no commits)."
                     )
 
-                entry: Dict[str, Any] = {
+                entry: dict[str, Any] = {
                     "provider": provider,
                     "account": account,
                     "repository": repo_name,
diff --git a/src/pkgmgr/actions/install/__init__.py b/src/pkgmgr/actions/install/__init__.py
index dac0267..e5e9194 100644
--- a/src/pkgmgr/actions/install/__init__.py
+++ b/src/pkgmgr/actions/install/__init__.py
@@ -1,6 +1,4 @@
 # src/pkgmgr/actions/install/__init__.py
-#!/usr/bin/env python3
-# -*- coding: utf-8 -*-
 
 """
 High-level entry point for repository installation.
@@ -16,7 +14,7 @@ Responsibilities:
 from __future__ import annotations
 
 import os
-from typing import Any, Dict, List, Optional, Tuple
+from typing import Any
 
 from pkgmgr.actions.install.context import RepoContext
 from pkgmgr.actions.install.installers.makefile import (
@@ -37,7 +35,7 @@ from pkgmgr.core.repository.dir import get_repo_dir
 from pkgmgr.core.repository.identifier import get_repo_identifier
 from pkgmgr.core.repository.verify import verify_repository
 
-Repository = Dict[str, Any]
+Repository = dict[str, Any]
 
 INSTALLERS = [
     ArchPkgbuildInstaller(),
@@ -52,12 +50,12 @@ INSTALLERS = [
 def _ensure_repo_dir(
     repo: Repository,
     repositories_base_dir: str,
-    all_repos: List[Repository],
+    all_repos: list[Repository],
     preview: bool,
     no_verification: bool,
     clone_mode: str,
     identifier: str,
-) -> Optional[str]:
+) -> str | None:
     """
     Compute and, if necessary, clone the repository directory.
 
@@ -127,7 +125,7 @@ def _create_context(
     repo_dir: str,
     repositories_base_dir: str,
     bin_dir: str,
-    all_repos: List[Repository],
+    all_repos: list[Repository],
     no_verification: bool,
     preview: bool,
     quiet: bool,
@@ -155,10 +153,10 @@ def _create_context(
 
 
 def install_repos(
-    selected_repos: List[Repository],
+    selected_repos: list[Repository],
     repositories_base_dir: str,
     bin_dir: str,
-    all_repos: List[Repository],
+    all_repos: list[Repository],
     no_verification: bool,
     preview: bool,
     quiet: bool,
@@ -179,7 +177,7 @@ def install_repos(
     overall command never exits non-zero because of per-repository failures.
     """
     pipeline = InstallationPipeline(INSTALLERS)
-    failures: List[Tuple[str, str]] = []
+    failures: list[tuple[str, str]] = []
 
     for repo in selected_repos:
         identifier = get_repo_identifier(repo, all_repos)
diff --git a/src/pkgmgr/actions/install/capabilities.py b/src/pkgmgr/actions/install/capabilities.py
index 1770af7..5ac6168 100644
--- a/src/pkgmgr/actions/install/capabilities.py
+++ b/src/pkgmgr/actions/install/capabilities.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 Capability detection for pkgmgr.
 
@@ -35,7 +33,7 @@ import glob
 import os
 from abc import ABC, abstractmethod
 from collections.abc import Iterable
-from typing import TYPE_CHECKING, Optional
+from typing import TYPE_CHECKING
 
 if TYPE_CHECKING:
     from pkgmgr.actions.install.context import RepoContext
@@ -46,12 +44,12 @@ if TYPE_CHECKING:
 # ---------------------------------------------------------------------------
 
 
-def _read_text_if_exists(path: str) -> Optional[str]:
+def _read_text_if_exists(path: str) -> str | None:
     """Read a file as UTF-8 text, returning None if it does not exist or fails."""
     if not os.path.exists(path):
         return None
     try:
-        with open(path, "r", encoding="utf-8") as f:
+        with open(path, encoding="utf-8") as f:
             return f.read()
     except OSError:
         return None
@@ -75,12 +73,12 @@ def _scan_files_for_patterns(files: Iterable[str], patterns: Iterable[str]) -> b
     return False
 
 
-def _first_spec_file(repo_dir: str) -> Optional[str]:
+def _first_spec_file(repo_dir: str) -> str | None:
     """Return the first *.spec file in repo_dir, if any."""
     matches = glob.glob(os.path.join(repo_dir, "*.spec"))
     if not matches:
         return None
-    return sorted(matches)[0]
+    return min(matches)
 
 
 # ---------------------------------------------------------------------------
@@ -216,7 +214,7 @@ class MakeInstallCapability(CapabilityMatcher):
             if not os.path.exists(makefile):
                 return False
             try:
-                with open(makefile, "r", encoding="utf-8") as f:
+                with open(makefile, encoding="utf-8") as f:
                     for line in f:
                         if line.strip().startswith("install:"):
                             return True
@@ -360,7 +358,7 @@ def detect_capabilities(
 
 def resolve_effective_capabilities(
     ctx: RepoContext,
-    layers: Optional[Iterable[str]] = None,
+    layers: Iterable[str] | None = None,
 ) -> dict[str, set[str]]:
     """
     Resolve *effective* capabilities for each layer using a bottom-up strategy.
@@ -381,10 +379,7 @@ def resolve_effective_capabilities(
     This means *any* higher layer can overshadow a lower layer, not just
     a specific one like Nix. The resolver is completely generic.
     """
-    if layers is None:
-        layers_list = list(LAYER_ORDER)
-    else:
-        layers_list = list(layers)
+    layers_list = list(LAYER_ORDER) if layers is None else list(layers)
 
     raw_caps = detect_capabilities(ctx, layers_list)
     effective: dict[str, set[str]] = {layer: set() for layer in layers_list}
diff --git a/src/pkgmgr/actions/install/context.py b/src/pkgmgr/actions/install/context.py
index c69777c..c397f31 100644
--- a/src/pkgmgr/actions/install/context.py
+++ b/src/pkgmgr/actions/install/context.py
@@ -1,6 +1,4 @@
 # src/pkgmgr/actions/install/context.py
-#!/usr/bin/env python3
-# -*- coding: utf-8 -*-
 
 """
 Shared context object for repository installation steps.
@@ -10,19 +8,19 @@ they do not depend on global state or long parameter lists.
 """
 
 from dataclasses import dataclass
-from typing import Any, Dict, List
+from typing import Any
 
 
 @dataclass
 class RepoContext:
     """Container for all repository-related data used during installation."""
 
-    repo: Dict[str, Any]
+    repo: dict[str, Any]
     identifier: str
     repo_dir: str
     repositories_base_dir: str
     bin_dir: str
-    all_repos: List[Dict[str, Any]]
+    all_repos: list[dict[str, Any]]
 
     no_verification: bool
     preview: bool
diff --git a/src/pkgmgr/actions/install/installers/__init__.py b/src/pkgmgr/actions/install/installers/__init__.py
index 9694cbf..8038e58 100644
--- a/src/pkgmgr/actions/install/installers/__init__.py
+++ b/src/pkgmgr/actions/install/installers/__init__.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 Installer package for pkgmgr.
 
diff --git a/src/pkgmgr/actions/install/installers/base.py b/src/pkgmgr/actions/install/installers/base.py
index 28f1468..303f4d3 100644
--- a/src/pkgmgr/actions/install/installers/base.py
+++ b/src/pkgmgr/actions/install/installers/base.py
@@ -1,11 +1,9 @@
-#!/usr/bin/env python3
-
 """
 Base interface for all installer components in the pkgmgr installation pipeline.
 """
+from __future__ import annotations
 
 from abc import ABC, abstractmethod
-from typing import Optional, Set
 
 from pkgmgr.actions.install.capabilities import CAPABILITY_MATCHERS
 from pkgmgr.actions.install.context import RepoContext
@@ -23,9 +21,9 @@ class BaseInstaller(ABC):
     #   Examples: "nix", "python", "makefile".
     #   This is used by capability matchers to decide which patterns to
     #   search for in the repository.
-    layer: Optional[str] = None
+    layer: str | None = None
 
-    def discover_capabilities(self, ctx: RepoContext) -> Set[str]:
+    def discover_capabilities(self, ctx: RepoContext) -> set[str]:
         """
         Determine which logical capabilities this installer will provide
         for this specific repository instance.
@@ -35,7 +33,7 @@ class BaseInstaller(ABC):
         Makefile, etc.) and decide, via string matching, whether a given
         capability is actually provided by this layer.
         """
-        caps: Set[str] = set()
+        caps: set[str] = set()
         if not self.layer:
             return caps
 
diff --git a/src/pkgmgr/actions/install/installers/makefile.py b/src/pkgmgr/actions/install/installers/makefile.py
index 5018f4f..9d173c6 100644
--- a/src/pkgmgr/actions/install/installers/makefile.py
+++ b/src/pkgmgr/actions/install/installers/makefile.py
@@ -26,16 +26,14 @@ class MakefileInstaller(BaseInstaller):
 
     def _has_install_target(self, makefile_path: str) -> bool:
         try:
-            with open(makefile_path, "r", encoding="utf-8", errors="ignore") as f:
+            with open(makefile_path, encoding="utf-8", errors="ignore") as f:
                 content = f.read()
         except OSError:
             return False
 
         if re.search(r"^install\s*:", content, flags=re.MULTILINE):
             return True
-        if re.search(r"^install-[a-zA-Z0-9_-]*\s*:", content, flags=re.MULTILINE):
-            return True
-        return False
+        return bool(re.search(r"^install-[a-zA-Z0-9_-]*\s*:", content, flags=re.MULTILINE))
 
     def run(self, ctx: RepoContext) -> None:
         makefile_path = os.path.join(ctx.repo_dir, self.MAKEFILE_NAME)
diff --git a/src/pkgmgr/actions/install/installers/nix/conflicts.py b/src/pkgmgr/actions/install/installers/nix/conflicts.py
index 65014ee..d722f92 100644
--- a/src/pkgmgr/actions/install/installers/nix/conflicts.py
+++ b/src/pkgmgr/actions/install/installers/nix/conflicts.py
@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import TYPE_CHECKING, List
+from typing import TYPE_CHECKING
 
 from .profile import NixProfileInspector
 from .retry import GitHubRateLimitRetry
@@ -49,7 +49,7 @@ class NixConflictResolver:
             store_prefixes = self._parser.existing_store_prefixes(combined)
 
             # 2) Resolve them to concrete remove tokens
-            tokens: List[str] = self._profile.find_remove_tokens_for_store_prefixes(
+            tokens: list[str] = self._profile.find_remove_tokens_for_store_prefixes(
                 ctx,
                 self._runner,
                 store_prefixes,
diff --git a/src/pkgmgr/actions/install/installers/nix/installer.py b/src/pkgmgr/actions/install/installers/nix/installer.py
index 79c207e..aef6c27 100644
--- a/src/pkgmgr/actions/install/installers/nix/installer.py
+++ b/src/pkgmgr/actions/install/installers/nix/installer.py
@@ -2,7 +2,7 @@ from __future__ import annotations
 
 import os
 import shutil
-from typing import TYPE_CHECKING, List, Tuple
+from typing import TYPE_CHECKING
 
 from pkgmgr.actions.install.installers.base import BaseInstaller
 
@@ -42,7 +42,7 @@ class NixFlakeInstaller(BaseInstaller):
 
         return os.path.exists(os.path.join(ctx.repo_dir, self.FLAKE_FILE))
 
-    def _profile_outputs(self, ctx: RepoContext) -> List[Tuple[str, bool]]:
+    def _profile_outputs(self, ctx: RepoContext) -> list[tuple[str, bool]]:
         # (output_name, allow_failure)
         if ctx.identifier in {"pkgmgr", "package-manager"}:
             return [("pkgmgr", False), ("default", True)]
diff --git a/src/pkgmgr/actions/install/installers/nix/profile/inspector.py b/src/pkgmgr/actions/install/installers/nix/profile/inspector.py
index c14163a..9d25b80 100644
--- a/src/pkgmgr/actions/install/installers/nix/profile/inspector.py
+++ b/src/pkgmgr/actions/install/installers/nix/profile/inspector.py
@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import TYPE_CHECKING, Any, List
+from typing import TYPE_CHECKING, Any
 
 from .matcher import (
     entry_matches_output,
@@ -43,11 +43,11 @@ class NixProfileInspector:
         ctx: RepoContext,
         runner: CommandRunner,
         output: str,
-    ) -> List[int]:
+    ) -> list[int]:
         data = self.list_json(ctx, runner)
         entries = normalize_elements(data)
 
-        hits: List[int] = []
+        hits: list[int] = []
         for e in entries:
             if e.index is None:
                 continue
@@ -61,7 +61,7 @@ class NixProfileInspector:
         ctx: RepoContext,
         runner: CommandRunner,
         store_path: str,
-    ) -> List[int]:
+    ) -> list[int]:
         needle = (store_path or "").strip()
         if not needle:
             return []
@@ -69,7 +69,7 @@ class NixProfileInspector:
         data = self.list_json(ctx, runner)
         entries = normalize_elements(data)
 
-        hits: List[int] = []
+        hits: list[int] = []
         for e in entries:
             if e.index is None:
                 continue
@@ -87,7 +87,7 @@ class NixProfileInspector:
         ctx: RepoContext,
         runner: CommandRunner,
         output: str,
-    ) -> List[str]:
+    ) -> list[str]:
         """
         Returns profile remove tokens to remove entries matching a given output.
 
@@ -101,7 +101,7 @@ class NixProfileInspector:
         data = self.list_json(ctx, runner)
         entries = normalize_elements(data)
 
-        tokens: List[str] = [
+        tokens: list[str] = [
             out
         ]  # critical: matches nix's own suggestion for conflicts
 
@@ -119,7 +119,7 @@ class NixProfileInspector:
 
         # stable unique preserving order
         seen: set[str] = set()
-        uniq: List[str] = []
+        uniq: list[str] = []
         for t in tokens:
             if t and t not in seen:
                 uniq.append(t)
@@ -130,8 +130,8 @@ class NixProfileInspector:
         self,
         ctx: RepoContext,
         runner: CommandRunner,
-        prefixes: List[str],
-    ) -> List[str]:
+        prefixes: list[str],
+    ) -> list[str]:
         """
         Returns remove tokens for entries whose store path matches any prefix.
         """
@@ -143,7 +143,7 @@ class NixProfileInspector:
         data = self.list_json(ctx, runner)
         entries = normalize_elements(data)
 
-        tokens: List[str] = []
+        tokens: list[str] = []
         for e in entries:
             if not e.store_paths:
                 continue
@@ -156,7 +156,7 @@ class NixProfileInspector:
                     tokens.append(n)
 
         seen: set[str] = set()
-        uniq: List[str] = []
+        uniq: list[str] = []
         for t in tokens:
             if t and t not in seen:
                 uniq.append(t)
diff --git a/src/pkgmgr/actions/install/installers/nix/profile/matcher.py b/src/pkgmgr/actions/install/installers/nix/profile/matcher.py
index 6d747c0..72b91f1 100644
--- a/src/pkgmgr/actions/install/installers/nix/profile/matcher.py
+++ b/src/pkgmgr/actions/install/installers/nix/profile/matcher.py
@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-from typing import List
-
 from .models import NixProfileEntry
 
 
@@ -51,9 +49,9 @@ def entry_matches_store_path(entry: NixProfileEntry, store_path: str) -> bool:
     return any((p or "") == needle for p in entry.store_paths)
 
 
-def stable_unique_ints(values: List[int]) -> List[int]:
+def stable_unique_ints(values: list[int]) -> list[int]:
     seen: set[int] = set()
-    uniq: List[int] = []
+    uniq: list[int] = []
     for v in values:
         if v in seen:
             continue
diff --git a/src/pkgmgr/actions/install/installers/nix/profile/models.py b/src/pkgmgr/actions/install/installers/nix/profile/models.py
index 1a23d62..72051a5 100644
--- a/src/pkgmgr/actions/install/installers/nix/profile/models.py
+++ b/src/pkgmgr/actions/install/installers/nix/profile/models.py
@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
-from typing import List, Optional
 
 
 @dataclass(frozen=True)
@@ -11,7 +10,7 @@ class NixProfileEntry:
     """
 
     key: str
-    index: Optional[int]
+    index: int | None
     name: str
     attr_path: str
-    store_paths: List[str]
+    store_paths: list[str]
diff --git a/src/pkgmgr/actions/install/installers/nix/profile/normalizer.py b/src/pkgmgr/actions/install/installers/nix/profile/normalizer.py
index 29674ad..19ac873 100644
--- a/src/pkgmgr/actions/install/installers/nix/profile/normalizer.py
+++ b/src/pkgmgr/actions/install/installers/nix/profile/normalizer.py
@@ -2,12 +2,12 @@ from __future__ import annotations
 
 import re
 from collections.abc import Iterable
-from typing import Any, Dict, List, Optional
+from typing import Any
 
 from .models import NixProfileEntry
 
 
-def coerce_index(key: str, entry: Dict[str, Any]) -> Optional[int]:
+def coerce_index(key: str, entry: dict[str, Any]) -> int | None:
     """
     Nix JSON schema varies:
       - elements keys might be "0", "1", ...
@@ -73,7 +73,7 @@ def iter_store_paths(entry: Dict[str, Any]) -> Iterable[str]:
 
     outs = entry.get("outputs")
     if isinstance(outs, dict):
-        for _, ov in outs.items():
+        for ov in outs.values():
             if isinstance(ov, dict):
                 p = ov.get("storePath")
                 if isinstance(p, str):
@@ -88,7 +88,7 @@ def normalize_store_path(store_path: str) -> str:
     return (store_path or "").strip()
 
 
-def normalize_elements(data: Dict[str, Any]) -> List[NixProfileEntry]:
+def normalize_elements(data: dict[str, Any]) -> list[NixProfileEntry]:
     """
     Converts nix profile list JSON into a list of normalized entries.
 
@@ -100,7 +100,7 @@ def normalize_elements(data: Dict[str, Any]) -> List[NixProfileEntry]:
     if not isinstance(elements, dict):
         return []
 
-    normalized: List[NixProfileEntry] = []
+    normalized: list[NixProfileEntry] = []
 
     for k, entry in elements.items():
         if not isinstance(entry, dict):
@@ -110,7 +110,7 @@ def normalize_elements(data: Dict[str, Any]) -> List[NixProfileEntry]:
         name = str(entry.get("name", "") or "")
         attr = str(entry.get("attrPath", "") or "")
 
-        store_paths: List[str] = []
+        store_paths: list[str] = []
         for p in iter_store_paths(entry):
             sp = normalize_store_path(p)
             if sp:
diff --git a/src/pkgmgr/actions/install/installers/nix/profile/parser.py b/src/pkgmgr/actions/install/installers/nix/profile/parser.py
index c7e5a89..106be83 100644
--- a/src/pkgmgr/actions/install/installers/nix/profile/parser.py
+++ b/src/pkgmgr/actions/install/installers/nix/profile/parser.py
@@ -1,10 +1,10 @@
 from __future__ import annotations
 
 import json
-from typing import Any, Dict
+from typing import Any
 
 
-def parse_profile_list_json(raw: str) -> Dict[str, Any]:
+def parse_profile_list_json(raw: str) -> dict[str, Any]:
     """
     Parse JSON output from `nix profile list --json`.
 
diff --git a/src/pkgmgr/actions/install/installers/nix/profile_list.py b/src/pkgmgr/actions/install/installers/nix/profile_list.py
index 302af7a..4aea026 100644
--- a/src/pkgmgr/actions/install/installers/nix/profile_list.py
+++ b/src/pkgmgr/actions/install/installers/nix/profile_list.py
@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 import re
-from typing import TYPE_CHECKING, List, Tuple
+from typing import TYPE_CHECKING
 
 from .runner import CommandRunner
 
@@ -19,12 +19,12 @@ class NixProfileListReader:
         m = re.match(r"^(/nix/store/[0-9a-z]{32}-[^/ \t]+)", raw)
         return m.group(1) if m else raw
 
-    def entries(self, ctx: RepoContext) -> List[Tuple[int, str]]:
+    def entries(self, ctx: RepoContext) -> list[tuple[int, str]]:
         res = self._runner.run(ctx, "nix profile list", allow_failure=True)
         if res.returncode != 0:
             return []
 
-        entries: List[Tuple[int, str]] = []
+        entries: list[tuple[int, str]] = []
         pat = re.compile(
             r"^\s*(\d+)\s+.*?(/nix/store/[0-9a-z]{32}-[^/ \t]+)",
             re.MULTILINE,
@@ -49,20 +49,20 @@ class NixProfileListReader:
         return uniq
 
     def indices_matching_store_prefixes(
-        self, ctx: RepoContext, prefixes: List[str]
-    ) -> List[int]:
+        self, ctx: RepoContext, prefixes: list[str]
+    ) -> list[int]:
         prefixes = [self._store_prefix(p) for p in prefixes if p]
         prefixes = [p for p in prefixes if p]
         if not prefixes:
             return []
 
-        hits: List[int] = []
+        hits: list[int] = []
         for idx, sp in self.entries(ctx):
             if any(sp == p for p in prefixes):
                 hits.append(idx)
 
         seen: set[int] = set()
-        uniq: List[int] = []
+        uniq: list[int] = []
         for i in hits:
             if i not in seen:
                 seen.add(i)
diff --git a/src/pkgmgr/actions/install/installers/nix/runner.py b/src/pkgmgr/actions/install/installers/nix/runner.py
index 3638ff8..14af1c1 100644
--- a/src/pkgmgr/actions/install/installers/nix/runner.py
+++ b/src/pkgmgr/actions/install/installers/nix/runner.py
@@ -31,8 +31,7 @@ class CommandRunner:
                 shell=True,
                 cwd=repo_dir,
                 check=False,
-                stdout=subprocess.PIPE,
-                stderr=subprocess.PIPE,
+                capture_output=True,
                 text=True,
             )
         except Exception as e:
diff --git a/src/pkgmgr/actions/install/installers/nix/textparse.py b/src/pkgmgr/actions/install/installers/nix/textparse.py
index ac5dad7..3e0886b 100644
--- a/src/pkgmgr/actions/install/installers/nix/textparse.py
+++ b/src/pkgmgr/actions/install/installers/nix/textparse.py
@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 import re
-from typing import List
 
 
 class NixConflictTextParser:
@@ -11,13 +10,13 @@ class NixConflictTextParser:
         m = re.match(r"^(/nix/store/[0-9a-z]{32}-[^/ \t]+)", raw)
         return m.group(1) if m else raw
 
-    def remove_tokens(self, text: str) -> List[str]:
+    def remove_tokens(self, text: str) -> list[str]:
         pat = re.compile(
             r"^\s*nix profile remove\s+([^\s'\"`]+|'[^']+'|\"[^\"]+\")\s*$",
             re.MULTILINE,
         )
 
-        tokens: List[str] = []
+        tokens: list[str] = []
         for m in pat.finditer(text or ""):
             t = (m.group(1) or "").strip()
             if (t.startswith("'") and t.endswith("'")) or (
@@ -28,7 +27,7 @@ class NixConflictTextParser:
                 tokens.append(t)
 
         seen: set[str] = set()
-        uniq: List[str] = []
+        uniq: list[str] = []
         for t in tokens:
             if t not in seen:
                 seen.add(t)
@@ -36,9 +35,9 @@ class NixConflictTextParser:
 
         return uniq
 
-    def existing_store_prefixes(self, text: str) -> List[str]:
+    def existing_store_prefixes(self, text: str) -> list[str]:
         lines = (text or "").splitlines()
-        prefixes: List[str] = []
+        prefixes: list[str] = []
 
         in_existing = False
         in_new = False
@@ -69,7 +68,7 @@ class NixConflictTextParser:
         norm = [self._store_prefix(p) for p in prefixes if p]
 
         seen: set[str] = set()
-        uniq: List[str] = []
+        uniq: list[str] = []
         for p in norm:
             if p and p not in seen:
                 seen.add(p)
diff --git a/src/pkgmgr/actions/install/installers/os_packages/debian_control.py b/src/pkgmgr/actions/install/installers/os_packages/debian_control.py
index ea1eeaf..cc4f62e 100644
--- a/src/pkgmgr/actions/install/installers/os_packages/debian_control.py
+++ b/src/pkgmgr/actions/install/installers/os_packages/debian_control.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 Installer for Debian/Ubuntu packages defined via debian/control.
 
@@ -12,11 +10,11 @@ This installer:
 It is intended for Debian-based systems where dpkg-buildpackage and
 apt/dpkg tooling are available.
 """
+from __future__ import annotations
 
 import glob
 import os
 import shutil
-from typing import List, Optional
 
 from pkgmgr.actions.install.context import RepoContext
 from pkgmgr.actions.install.installers.base import BaseInstaller
@@ -55,7 +53,7 @@ class DebianControlInstaller(BaseInstaller):
 
         return os.path.exists(self._control_path(ctx))
 
-    def _find_built_debs(self, repo_dir: str) -> List[str]:
+    def _find_built_debs(self, repo_dir: str) -> list[str]:
         """
         Find .deb files built by dpkg-buildpackage.
 
@@ -66,7 +64,7 @@ class DebianControlInstaller(BaseInstaller):
         pattern = os.path.join(parent, "*.deb")
         return sorted(glob.glob(pattern))
 
-    def _privileged_prefix(self) -> Optional[str]:
+    def _privileged_prefix(self) -> str | None:
         """
         Determine how to run privileged commands:
 
diff --git a/src/pkgmgr/actions/install/installers/os_packages/rpm_spec.py b/src/pkgmgr/actions/install/installers/os_packages/rpm_spec.py
index 00248c7..62c5f17 100644
--- a/src/pkgmgr/actions/install/installers/os_packages/rpm_spec.py
+++ b/src/pkgmgr/actions/install/installers/os_packages/rpm_spec.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 Installer for RPM-based packages defined in *.spec files.
 
@@ -13,12 +11,12 @@ This installer:
 
 It targets RPM-based systems (Fedora / RHEL / CentOS / Rocky / Alma, etc.).
 """
+from __future__ import annotations
 
 import glob
 import os
 import shutil
 import tarfile
-from typing import List, Optional, Tuple
 
 from pkgmgr.actions.install.context import RepoContext
 from pkgmgr.actions.install.installers.base import BaseInstaller
@@ -52,7 +50,7 @@ class RpmSpecInstaller(BaseInstaller):
 
         return has_dnf or has_yum or has_yum_builddep
 
-    def _spec_path(self, ctx: RepoContext) -> Optional[str]:
+    def _spec_path(self, ctx: RepoContext) -> str | None:
         """Return the first *.spec file in the repository root, if any."""
         pattern = os.path.join(ctx.repo_dir, "*.spec")
         matches = sorted(glob.glob(pattern))
@@ -91,7 +89,7 @@ class RpmSpecInstaller(BaseInstaller):
         for sub in ("BUILD", "BUILDROOT", "RPMS", "SOURCES", "SPECS", "SRPMS"):
             os.makedirs(os.path.join(topdir, sub), exist_ok=True)
 
-    def _parse_name_version(self, spec_path: str) -> Optional[Tuple[str, str]]:
+    def _parse_name_version(self, spec_path: str) -> tuple[str, str] | None:
         """
         Parse Name and Version from the given .spec file.
 
@@ -100,7 +98,7 @@ class RpmSpecInstaller(BaseInstaller):
         name = None
         version = None
 
-        with open(spec_path, "r", encoding="utf-8") as f:
+        with open(spec_path, encoding="utf-8") as f:
             for raw_line in f:
                 line = raw_line.strip()
                 # Ignore comments
@@ -182,7 +180,7 @@ class RpmSpecInstaller(BaseInstaller):
 
         return self._spec_path(ctx) is not None
 
-    def _find_built_rpms(self) -> List[str]:
+    def _find_built_rpms(self) -> list[str]:
         """
         Find RPMs built by rpmbuild.
 
@@ -212,7 +210,7 @@ class RpmSpecInstaller(BaseInstaller):
 
         run_command(cmd, cwd=ctx.repo_dir, preview=ctx.preview)
 
-    def _install_built_rpms(self, ctx: RepoContext, rpms: List[str]) -> None:
+    def _install_built_rpms(self, ctx: RepoContext, rpms: list[str]) -> None:
         """
         Install or upgrade the built RPMs.
 
diff --git a/src/pkgmgr/actions/install/layers.py b/src/pkgmgr/actions/install/layers.py
index f36d081..fbd967a 100644
--- a/src/pkgmgr/actions/install/layers.py
+++ b/src/pkgmgr/actions/install/layers.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 CLI layer model for the pkgmgr installation pipeline.
 
@@ -18,7 +16,6 @@ from __future__ import annotations
 
 import os
 from enum import Enum
-from typing import Optional
 
 
 class CliLayer(str, Enum):
@@ -37,7 +34,7 @@ CLI_LAYERS: list[CliLayer] = [
 ]
 
 
-def layer_priority(layer: Optional[CliLayer]) -> int:
+def layer_priority(layer: CliLayer | None) -> int:
     """
     Return a numeric priority index for a given layer.
 
@@ -69,13 +66,11 @@ def classify_command_layer(command: str, repo_dir: str) -> CliLayer:
     home = os.path.expanduser("~")
 
     # OS package managers
-    if command_abs.startswith("/usr/") or command_abs.startswith("/bin/"):
+    if command_abs.startswith(("/usr/", "/bin/")):
         return CliLayer.OS_PACKAGES
 
     # Nix store / profile
-    if command_abs.startswith("/nix/store/") or command_abs.startswith(
-        os.path.join(home, ".nix-profile")
-    ):
+    if command_abs.startswith(("/nix/store/", os.path.join(home, ".nix-profile"))):
         return CliLayer.NIX
 
     # User-local bin
diff --git a/src/pkgmgr/actions/install/pipeline.py b/src/pkgmgr/actions/install/pipeline.py
index f32f37f..0d5e3e9 100644
--- a/src/pkgmgr/actions/install/pipeline.py
+++ b/src/pkgmgr/actions/install/pipeline.py
@@ -1,6 +1,4 @@
 # src/pkgmgr/actions/install/pipeline.py
-#!/usr/bin/env python3
-# -*- coding: utf-8 -*-
 
 """
 Installation pipeline orchestration for repositories.
@@ -10,7 +8,6 @@ from __future__ import annotations
 
 from collections.abc import Sequence
 from dataclasses import dataclass
-from typing import Optional, Set
 
 from pkgmgr.actions.install.context import RepoContext
 from pkgmgr.actions.install.installers.base import BaseInstaller
@@ -25,8 +22,8 @@ from pkgmgr.core.command.resolve import resolve_command_for_repo
 
 @dataclass
 class CommandState:
-    command: Optional[str]
-    layer: Optional[CliLayer]
+    command: str | None
+    layer: CliLayer | None
 
 
 class CommandResolver:
@@ -84,7 +81,7 @@ class InstallationPipeline:
         else:
             repo.pop("command", None)
 
-        provided_capabilities: Set[str] = set()
+        provided_capabilities: set[str] = set()
 
         for installer in self._installers:
             layer_name = getattr(installer, "layer", None)
diff --git a/src/pkgmgr/actions/mirror/context.py b/src/pkgmgr/actions/mirror/context.py
index 22591ee..93d3c51 100644
--- a/src/pkgmgr/actions/mirror/context.py
+++ b/src/pkgmgr/actions/mirror/context.py
@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-from typing import List
-
 from pkgmgr.core.repository.dir import get_repo_dir
 from pkgmgr.core.repository.identifier import get_repo_identifier
 
@@ -12,7 +10,7 @@ from .types import MirrorMap, RepoMirrorContext, Repository
 def build_context(
     repo: Repository,
     repositories_base_dir: str,
-    all_repos: List[Repository],
+    all_repos: list[Repository],
 ) -> RepoMirrorContext:
     """
     Build a RepoMirrorContext for a single repository.
diff --git a/src/pkgmgr/actions/mirror/diff_cmd.py b/src/pkgmgr/actions/mirror/diff_cmd.py
index 3b467b8..a266bcf 100644
--- a/src/pkgmgr/actions/mirror/diff_cmd.py
+++ b/src/pkgmgr/actions/mirror/diff_cmd.py
@@ -1,16 +1,14 @@
 from __future__ import annotations
 
-from typing import List
-
 from .context import build_context
 from .printing import print_header
 from .types import Repository
 
 
 def diff_mirrors(
-    selected_repos: List[Repository],
+    selected_repos: list[Repository],
     repositories_base_dir: str,
-    all_repos: List[Repository],
+    all_repos: list[Repository],
 ) -> None:
     """
     Show differences between config mirrors and MIRRORS file.
diff --git a/src/pkgmgr/actions/mirror/git_remote.py b/src/pkgmgr/actions/mirror/git_remote.py
index c0daec2..9334c66 100644
--- a/src/pkgmgr/actions/mirror/git_remote.py
+++ b/src/pkgmgr/actions/mirror/git_remote.py
@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 import os
-from typing import Optional, Set
 
 from pkgmgr.core.git.commands import (
     GitAddRemoteError,
@@ -38,13 +37,10 @@ def _is_git_remote_url(url: str) -> bool:
     if u.startswith("ssh://"):
         return True
 
-    if (u.startswith("https://") or u.startswith("http://")) and u.endswith(".git"):
-        return True
-
-    return False
+    return bool((u.startswith(("https://", "http://"))) and u.endswith(".git"))
 
 
-def build_default_ssh_url(repo: Repository) -> Optional[str]:
+def build_default_ssh_url(repo: Repository) -> str | None:
     provider = repo.get("provider")
     account = repo.get("account")
     name = repo.get("repository")
@@ -66,7 +62,7 @@ def _git_mirrors_only(m: MirrorMap) -> MirrorMap:
 def determine_primary_remote_url(
     repo: Repository,
     ctx: RepoMirrorContext,
-) -> Optional[str]:
+) -> str | None:
     """
     Priority order (GIT URLS ONLY):
       1. origin from resolved mirrors (if it is a git URL)
@@ -80,7 +76,7 @@ def determine_primary_remote_url(
         return origin
 
     for mirrors in (ctx.file_mirrors, ctx.config_mirrors):
-        for _, url in mirrors.items():
+        for url in mirrors.values():
             if url and _is_git_remote_url(url):
                 return url
 
@@ -116,7 +112,7 @@ def _ensure_additional_push_urls(
     Non-git URLs (like PyPI) are ignored and will never land in git config.
     """
     git_only = _git_mirrors_only(mirrors)
-    desired: Set[str] = {u for u in git_only.values() if u and u != primary}
+    desired: set[str] = {u for u in git_only.values() if u and u != primary}
     if not desired:
         return
 
diff --git a/src/pkgmgr/actions/mirror/io.py b/src/pkgmgr/actions/mirror/io.py
index c5c9098..18588d4 100644
--- a/src/pkgmgr/actions/mirror/io.py
+++ b/src/pkgmgr/actions/mirror/io.py
@@ -42,7 +42,7 @@ def read_mirrors_file(repo_dir: str, filename: str = "MIRRORS") -> MirrorMap:
         return mirrors
 
     try:
-        with open(path, "r", encoding="utf-8") as fh:
+        with open(path, encoding="utf-8") as fh:
             for line in fh:
                 stripped = line.strip()
                 if not stripped or stripped.startswith("#"):
diff --git a/src/pkgmgr/actions/mirror/list_cmd.py b/src/pkgmgr/actions/mirror/list_cmd.py
index a3b094a..ffa3763 100644
--- a/src/pkgmgr/actions/mirror/list_cmd.py
+++ b/src/pkgmgr/actions/mirror/list_cmd.py
@@ -1,16 +1,14 @@
 from __future__ import annotations
 
-from typing import List
-
 from .context import build_context
 from .printing import print_header, print_named_mirrors
 from .types import Repository
 
 
 def list_mirrors(
-    selected_repos: List[Repository],
+    selected_repos: list[Repository],
     repositories_base_dir: str,
-    all_repos: List[Repository],
+    all_repos: list[Repository],
     source: str = "all",
 ) -> None:
     """
diff --git a/src/pkgmgr/actions/mirror/merge_cmd.py b/src/pkgmgr/actions/mirror/merge_cmd.py
index 7f9cca8..ac17548 100644
--- a/src/pkgmgr/actions/mirror/merge_cmd.py
+++ b/src/pkgmgr/actions/mirror/merge_cmd.py
@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 import os
-from typing import Dict, List, Optional, Tuple
 
 import yaml
 
@@ -16,7 +15,7 @@ from .types import MirrorMap, Repository
 # -----------------------------------------------------------------------------
 
 
-def _repo_key(repo: Repository) -> Tuple[str, str, str]:
+def _repo_key(repo: Repository) -> tuple[str, str, str]:
     """
     Normalised key for identifying a repository in config files.
     """
@@ -27,7 +26,7 @@ def _repo_key(repo: Repository) -> Tuple[str, str, str]:
     )
 
 
-def _load_user_config(path: str) -> Dict[str, object]:
+def _load_user_config(path: str) -> dict[str, object]:
     """
     Load a user config YAML file as dict.
     Non-dicts yield {}.
@@ -49,13 +48,13 @@ def _load_user_config(path: str) -> Dict[str, object]:
 
 
 def merge_mirrors(
-    selected_repos: List[Repository],
+    selected_repos: list[Repository],
     repositories_base_dir: str,
-    all_repos: List[Repository],
+    all_repos: list[Repository],
     source: str,
     target: str,
     preview: bool = False,
-    user_config_path: Optional[str] = None,
+    user_config_path: str | None = None,
 ) -> None:
     """
     Merge mirrors between config and MIRRORS file.
@@ -73,8 +72,8 @@ def merge_mirrors(
     """
 
     # Load user config once if we intend to write to it.
-    user_cfg: Optional[Dict[str, object]] = None
-    user_cfg_path_expanded: Optional[str] = None
+    user_cfg: dict[str, object] | None = None
+    user_cfg_path_expanded: str | None = None
 
     if target == "config" and user_config_path and not preview:
         user_cfg_path_expanded = os.path.expanduser(user_config_path)
@@ -129,7 +128,7 @@ def merge_mirrors(
 
             repos = user_cfg.get("repositories")
             target_key = _repo_key(repo)
-            existing_repo: Optional[Repository] = None
+            existing_repo: Repository | None = None
 
             # Find existing repo entry
             for entry in repos:
diff --git a/src/pkgmgr/actions/mirror/remote_provision.py b/src/pkgmgr/actions/mirror/remote_provision.py
index a7faf37..970ae59 100644
--- a/src/pkgmgr/actions/mirror/remote_provision.py
+++ b/src/pkgmgr/actions/mirror/remote_provision.py
@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-from typing import List
-
 from pkgmgr.core.remote_provisioning import ProviderHint, RepoSpec, ensure_remote_repo
 from pkgmgr.core.remote_provisioning.ensure import EnsureOptions
 
@@ -64,7 +62,7 @@ def ensure_remote_repository_for_url(
 def ensure_remote_repository(
     repo: Repository,
     repositories_base_dir: str,
-    all_repos: List[Repository],
+    all_repos: list[Repository],
     preview: bool,
 ) -> None:
     """
diff --git a/src/pkgmgr/actions/mirror/setup_cmd.py b/src/pkgmgr/actions/mirror/setup_cmd.py
index fe22014..78194c2 100644
--- a/src/pkgmgr/actions/mirror/setup_cmd.py
+++ b/src/pkgmgr/actions/mirror/setup_cmd.py
@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-from typing import List
-
 from pkgmgr.core.git.queries import probe_remote_reachable_detail
 from pkgmgr.core.remote_provisioning import ProviderHint, RepoSpec, set_repo_visibility
 from pkgmgr.core.remote_provisioning.visibility import VisibilityOptions
@@ -23,9 +21,7 @@ def _is_git_remote_url(url: str) -> bool:
         return True
     if u.startswith("ssh://"):
         return True
-    if (u.startswith("https://") or u.startswith("http://")) and u.endswith(".git"):
-        return True
-    return False
+    return bool((u.startswith(("https://", "http://"))) and u.endswith(".git"))
 
 
 def _provider_hint_from_host(host: str) -> str | None:
@@ -89,7 +85,7 @@ def _print_probe_result(name: str | None, url: str, *, cwd: str) -> None:
 def _setup_local_mirrors_for_repo(
     repo: Repository,
     repositories_base_dir: str,
-    all_repos: List[Repository],
+    all_repos: list[Repository],
     preview: bool,
 ) -> None:
     ctx = build_context(repo, repositories_base_dir, all_repos)
@@ -106,7 +102,7 @@ def _setup_local_mirrors_for_repo(
 def _setup_remote_mirrors_for_repo(
     repo: Repository,
     repositories_base_dir: str,
-    all_repos: List[Repository],
+    all_repos: list[Repository],
     preview: bool,
     ensure_remote: bool,
     ensure_visibility: str | None,
@@ -195,9 +191,9 @@ def _setup_remote_mirrors_for_repo(
 
 
 def setup_mirrors(
-    selected_repos: List[Repository],
+    selected_repos: list[Repository],
     repositories_base_dir: str,
-    all_repos: List[Repository],
+    all_repos: list[Repository],
     preview: bool = False,
     local: bool = True,
     remote: bool = True,
diff --git a/src/pkgmgr/actions/mirror/types.py b/src/pkgmgr/actions/mirror/types.py
index a95bf80..aae93d5 100644
--- a/src/pkgmgr/actions/mirror/types.py
+++ b/src/pkgmgr/actions/mirror/types.py
@@ -1,10 +1,10 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
-from typing import Any, Dict
+from typing import Any
 
-Repository = Dict[str, Any]
-MirrorMap = Dict[str, str]
+Repository = dict[str, Any]
+MirrorMap = dict[str, str]
 
 
 @dataclass(frozen=True)
diff --git a/src/pkgmgr/actions/mirror/url_utils.py b/src/pkgmgr/actions/mirror/url_utils.py
index 8515435..0935caa 100644
--- a/src/pkgmgr/actions/mirror/url_utils.py
+++ b/src/pkgmgr/actions/mirror/url_utils.py
@@ -1,11 +1,10 @@
 # src/pkgmgr/actions/mirror/url_utils.py
 from __future__ import annotations
 
-from typing import Optional, Tuple
 from urllib.parse import urlparse
 
 
-def hostport_from_git_url(url: str) -> Tuple[str, Optional[str]]:
+def hostport_from_git_url(url: str) -> tuple[str, str | None]:
     url = (url or "").strip()
     if not url:
         return "", None
@@ -58,7 +57,7 @@ def _strip_dot_git(name: str) -> str:
     return n
 
 
-def parse_repo_from_git_url(url: str) -> Tuple[str, Optional[str], Optional[str]]:
+def parse_repo_from_git_url(url: str) -> tuple[str, str | None, str | None]:
     """
     Parse (host, owner, repo_name) from common Git remote URLs.
 
diff --git a/src/pkgmgr/actions/mirror/visibility_cmd.py b/src/pkgmgr/actions/mirror/visibility_cmd.py
index 6d16e62..ef13001 100644
--- a/src/pkgmgr/actions/mirror/visibility_cmd.py
+++ b/src/pkgmgr/actions/mirror/visibility_cmd.py
@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-from typing import List
-
 from pkgmgr.core.remote_provisioning import ProviderHint, RepoSpec, set_repo_visibility
 from pkgmgr.core.remote_provisioning.visibility import VisibilityOptions
 
@@ -20,9 +18,7 @@ def _is_git_remote_url(url: str) -> bool:
         return True
     if u.startswith("ssh://"):
         return True
-    if (u.startswith("https://") or u.startswith("http://")) and u.endswith(".git"):
-        return True
-    return False
+    return bool((u.startswith(("https://", "http://"))) and u.endswith(".git"))
 
 
 def _provider_hint_from_host(host: str) -> str | None:
@@ -66,9 +62,9 @@ def _apply_visibility_for_url(
 
 
 def set_mirror_visibility(
-    selected_repos: List[Repository],
+    selected_repos: list[Repository],
     repositories_base_dir: str,
-    all_repos: List[Repository],
+    all_repos: list[Repository],
     *,
     visibility: str,
     preview: bool = False,
diff --git a/src/pkgmgr/actions/release/files/__init__.py b/src/pkgmgr/actions/release/files/__init__.py
index 3c56045..e09f468 100644
--- a/src/pkgmgr/actions/release/files/__init__.py
+++ b/src/pkgmgr/actions/release/files/__init__.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 Backwards-compatible facade for the release file update helpers.
 
diff --git a/src/pkgmgr/actions/release/files/changelog_lint.py b/src/pkgmgr/actions/release/files/changelog_lint.py
index 5fa5335..eea7ba1 100644
--- a/src/pkgmgr/actions/release/files/changelog_lint.py
+++ b/src/pkgmgr/actions/release/files/changelog_lint.py
@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import contextlib
 import os
 import re
 import shutil
@@ -70,6 +71,7 @@ def _markdownlint(reference_path: str, document: str) -> list[str]:
             cwd=directory,
             capture_output=True,
             text=True,
+            check=False,
         )
         if proc.returncode == 0:
             return []
diff --git a/src/pkgmgr/actions/release/files/changelog_md.py b/src/pkgmgr/actions/release/files/changelog_md.py
index af50f15..9b3d0f9 100644
--- a/src/pkgmgr/actions/release/files/changelog_md.py
+++ b/src/pkgmgr/actions/release/files/changelog_md.py
@@ -4,7 +4,6 @@ import os
 import re
 import sys
 from datetime import date
-from typing import Optional
 
 from .changelog_lint import (
     ChangelogLintError,
@@ -55,7 +54,7 @@ def _insert_after_h1(existing: str, entry: str) -> str:
 def update_changelog(
     changelog_path: str,
     new_version: str,
-    message: Optional[str] = None,
+    message: str | None = None,
     preview: bool = False,
 ) -> str:
     """Insert a new release entry into CHANGELOG.md.
@@ -87,7 +86,7 @@ def update_changelog(
     elif preview or not sys.stdin.isatty():
         body, entry = _entry_for(message or f"Release {new_version}")
     else:
-        attempt: Optional[str] = None
+        attempt: str | None = None
         while True:
             print(
                 "\n[INFO] Provide the changelog entry — a leading '#' becomes "
diff --git a/src/pkgmgr/actions/release/files/debian.py b/src/pkgmgr/actions/release/files/debian.py
index b0d6c03..5288669 100644
--- a/src/pkgmgr/actions/release/files/debian.py
+++ b/src/pkgmgr/actions/release/files/debian.py
@@ -2,12 +2,11 @@ from __future__ import annotations
 
 import os
 from datetime import datetime
-from typing import Optional, Tuple
 
 from pkgmgr.core.git.queries import get_config_value
 
 
-def _get_debian_author() -> Tuple[str, str]:
+def _get_debian_author() -> tuple[str, str]:
     name = os.environ.get("DEBFULLNAME")
     email = os.environ.get("DEBEMAIL")
 
@@ -33,7 +32,7 @@ def update_debian_changelog(
     debian_changelog_path: str,
     package_name: str,
     new_version: str,
-    message: Optional[str] = None,
+    message: str | None = None,
     preview: bool = False,
 ) -> None:
     if not os.path.exists(debian_changelog_path):
diff --git a/src/pkgmgr/actions/release/files/editor.py b/src/pkgmgr/actions/release/files/editor.py
index fd54018..a990548 100644
--- a/src/pkgmgr/actions/release/files/editor.py
+++ b/src/pkgmgr/actions/release/files/editor.py
@@ -1,12 +1,12 @@
 from __future__ import annotations
 
+import contextlib
 import os
 import subprocess
 import tempfile
-from typing import Optional
 
 
-def _open_editor_for_changelog(initial_message: Optional[str] = None) -> str:
+def _open_editor_for_changelog(initial_message: str | None = None) -> str:
     editor = os.environ.get("EDITOR", "nano")
 
     with tempfile.NamedTemporaryFile(
diff --git a/src/pkgmgr/actions/release/files/pyproject.py b/src/pkgmgr/actions/release/files/pyproject.py
index afefb39..1547513 100644
--- a/src/pkgmgr/actions/release/files/pyproject.py
+++ b/src/pkgmgr/actions/release/files/pyproject.py
@@ -12,7 +12,7 @@ def update_pyproject_version(
         return
 
     try:
-        with open(pyproject_path, "r", encoding="utf-8") as f:
+        with open(pyproject_path, encoding="utf-8") as f:
             content = f.read()
     except OSError as exc:
         print(f"[WARN] Could not read pyproject.toml: {exc}")
diff --git a/src/pkgmgr/actions/release/files/rpm_changelog.py b/src/pkgmgr/actions/release/files/rpm_changelog.py
index 586a204..fbada7f 100644
--- a/src/pkgmgr/actions/release/files/rpm_changelog.py
+++ b/src/pkgmgr/actions/release/files/rpm_changelog.py
@@ -2,7 +2,6 @@ from __future__ import annotations
 
 import os
 from datetime import datetime
-from typing import Optional
 
 from .debian import _get_debian_author
 
@@ -11,7 +10,7 @@ def update_spec_changelog(
     spec_path: str,
     package_name: str,
     new_version: str,
-    message: Optional[str] = None,
+    message: str | None = None,
     preview: bool = False,
 ) -> None:
     if not os.path.exists(spec_path):
diff --git a/src/pkgmgr/actions/release/package_name.py b/src/pkgmgr/actions/release/package_name.py
index 0306634..80cab36 100644
--- a/src/pkgmgr/actions/release/package_name.py
+++ b/src/pkgmgr/actions/release/package_name.py
@@ -24,7 +24,6 @@ from __future__ import annotations
 
 import os
 import re
-from typing import Optional
 
 from pkgmgr.core.repository.paths import RepoPaths
 
@@ -33,17 +32,17 @@ _PKGBUILD_NAME_RE = re.compile(r"^pkgname=([^\s#]+)\s*$", re.MULTILINE)
 _RPM_NAME_RE = re.compile(r"^Name:\s*(\S+)\s*$", re.MULTILINE)
 
 
-def _read(path: Optional[str]) -> str:
+def _read(path: str | None) -> str:
     if not path or not os.path.isfile(path):
         return ""
     try:
-        with open(path, "r", encoding="utf-8") as f:
+        with open(path, encoding="utf-8") as f:
             return f.read()
     except OSError:
         return ""
 
 
-def _extract(pattern: re.Pattern[str], text: str) -> Optional[str]:
+def _extract(pattern: re.Pattern[str], text: str) -> str | None:
     if not text:
         return None
     match = pattern.search(text)
diff --git a/src/pkgmgr/actions/release/versioning.py b/src/pkgmgr/actions/release/versioning.py
index 481e2f3..2d9c5cf 100644
--- a/src/pkgmgr/actions/release/versioning.py
+++ b/src/pkgmgr/actions/release/versioning.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 Version discovery and bumping helpers for the release workflow.
 """
diff --git a/src/pkgmgr/actions/release/workflow.py b/src/pkgmgr/actions/release/workflow.py
index 5888fcd..b4d6725 100644
--- a/src/pkgmgr/actions/release/workflow.py
+++ b/src/pkgmgr/actions/release/workflow.py
@@ -2,7 +2,6 @@ from __future__ import annotations
 
 import os
 import sys
-from typing import Optional
 
 from pkgmgr.actions.branch import close_branch
 from pkgmgr.core.git import GitRunError, run
@@ -34,7 +33,7 @@ def _release_impl(
     pyproject_path: str = "pyproject.toml",
     changelog_path: str = "CHANGELOG.md",
     release_type: str = "patch",
-    message: Optional[str] = None,
+    message: str | None = None,
     preview: bool = False,
     close: bool = False,
     force: bool = False,
@@ -87,7 +86,7 @@ def _release_impl(
     else:
         print("[INFO] No RPM spec file found. Skipping spec version update.")
 
-    effective_message: Optional[str] = message
+    effective_message: str | None = message
     if isinstance(changelog_message, str) and changelog_message.strip():
         effective_message = changelog_message.strip()
 
@@ -195,7 +194,7 @@ def release(
     pyproject_path: str = "pyproject.toml",
     changelog_path: str = "CHANGELOG.md",
     release_type: str = "patch",
-    message: Optional[str] = None,
+    message: str | None = None,
     preview: bool = False,
     force: bool = False,
     close: bool = False,
diff --git a/src/pkgmgr/actions/repository/_parallel.py b/src/pkgmgr/actions/repository/_parallel.py
index d931f3d..c7add17 100644
--- a/src/pkgmgr/actions/repository/_parallel.py
+++ b/src/pkgmgr/actions/repository/_parallel.py
@@ -3,29 +3,29 @@ from __future__ import annotations
 import os
 import sys
 from concurrent.futures import ThreadPoolExecutor, as_completed
-from typing import Any, Callable, Dict, List, Tuple
+from typing import Any, Callable
 
 from pkgmgr.core.repository.dir import get_repo_dir
 from pkgmgr.core.repository.identifier import get_repo_identifier
 
-Repository = Dict[str, Any]
-RepoRef = Tuple[str, str]
-OpResult = Tuple[bool, str]
+Repository = dict[str, Any]
+RepoRef = tuple[str, str]
+OpResult = tuple[bool, str]
 RepoOp = Callable[[str], OpResult]
 
 
 def resolve_repos(
-    selected_repos: List[Repository],
+    selected_repos: list[Repository],
     repositories_base_dir: str,
-    all_repos: List[Repository],
-) -> List[RepoRef]:
+    all_repos: list[Repository],
+) -> list[RepoRef]:
     """
     Resolve ``(identifier, repo_dir)`` pairs for ``selected_repos``.
 
     Repositories whose directory does not exist on disk are reported and
     skipped, matching the prior behavior of pull/push handlers.
     """
-    resolved: List[RepoRef] = []
+    resolved: list[RepoRef] = []
     for repo in selected_repos:
         ident = get_repo_identifier(repo, all_repos)
         rd = get_repo_dir(repositories_base_dir, repo)
@@ -37,7 +37,7 @@ def resolve_repos(
 
 
 def run_on_repos(
-    repos: List[RepoRef],
+    repos: list[RepoRef],
     op: RepoOp,
     *,
     jobs: int,
@@ -55,7 +55,7 @@ def run_on_repos(
         return
 
     effective_jobs = max(1, min(jobs, len(repos)))
-    failed: List[Tuple[str, str]] = []
+    failed: list[tuple[str, str]] = []
 
     if effective_jobs == 1:
         for ident, rd in repos:
diff --git a/src/pkgmgr/actions/repository/clone.py b/src/pkgmgr/actions/repository/clone.py
index 6fe7c88..d4e11d6 100644
--- a/src/pkgmgr/actions/repository/clone.py
+++ b/src/pkgmgr/actions/repository/clone.py
@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 import os
-from typing import Any, Dict, List, Optional
+from typing import Any
 
 from pkgmgr.core.git.commands import GitCloneError
 from pkgmgr.core.git.commands import clone as git_clone
@@ -9,10 +9,10 @@ from pkgmgr.core.repository.dir import get_repo_dir
 from pkgmgr.core.repository.identifier import get_repo_identifier
 from pkgmgr.core.repository.verify import verify_repository
 
-Repository = Dict[str, Any]
+Repository = dict[str, Any]
 
 
-def _build_clone_url(repo: Repository, clone_mode: str) -> Optional[str]:
+def _build_clone_url(repo: Repository, clone_mode: str) -> str | None:
     provider = repo.get("provider")
     account = repo.get("account")
     name = repo.get("repository")
@@ -34,9 +34,9 @@ def _build_clone_url(repo: Repository, clone_mode: str) -> Optional[str]:
 
 
 def clone_repos(
-    selected_repos: List[Repository],
+    selected_repos: list[Repository],
     repositories_base_dir: str,
-    all_repos: List[Repository],
+    all_repos: list[Repository],
     preview: bool,
     no_verification: bool,
     clone_mode: str,
diff --git a/src/pkgmgr/actions/repository/create/__init__.py b/src/pkgmgr/actions/repository/create/__init__.py
index 0ca6a49..3a980d0 100644
--- a/src/pkgmgr/actions/repository/create/__init__.py
+++ b/src/pkgmgr/actions/repository/create/__init__.py
@@ -1,10 +1,10 @@
 from __future__ import annotations
 
-from typing import Any, Dict
+from typing import Any
 
 from .service import CreateRepoService
 
-RepositoryConfig = Dict[str, Any]
+RepositoryConfig = dict[str, Any]
 
 __all__ = [
     "CreateRepoService",
diff --git a/src/pkgmgr/actions/repository/create/config_writer.py b/src/pkgmgr/actions/repository/create/config_writer.py
index 3711484..cf73f63 100644
--- a/src/pkgmgr/actions/repository/create/config_writer.py
+++ b/src/pkgmgr/actions/repository/create/config_writer.py
@@ -1,21 +1,21 @@
 from __future__ import annotations
 
 import os
-from typing import Any, Dict, Set
+from typing import Any
 
 import yaml
 
 from pkgmgr.core.command.alias import generate_alias
 from pkgmgr.core.config.save import save_user_config
 
-Repository = Dict[str, Any]
+Repository = dict[str, Any]
 
 
 class ConfigRepoWriter:
     def __init__(
         self,
         *,
-        config_merged: Dict[str, Any],
+        config_merged: dict[str, Any],
         user_config_path: str,
         bin_dir: str,
     ):
@@ -43,7 +43,7 @@ class ConfigRepoWriter:
             ):
                 return repo
 
-        existing_aliases: Set[str] = {
+        existing_aliases: set[str] = {
             str(r.get("alias")) for r in repositories if r.get("alias")
         }
 
@@ -70,7 +70,7 @@ class ConfigRepoWriter:
             return repo
 
         if os.path.exists(self.user_config_path):
-            with open(self.user_config_path, "r", encoding="utf-8") as f:
+            with open(self.user_config_path, encoding="utf-8") as f:
                 user_cfg = yaml.safe_load(f) or {}
         else:
             user_cfg = {}
diff --git a/src/pkgmgr/actions/repository/create/mirrors.py b/src/pkgmgr/actions/repository/create/mirrors.py
index 97917bb..da64a6c 100644
--- a/src/pkgmgr/actions/repository/create/mirrors.py
+++ b/src/pkgmgr/actions/repository/create/mirrors.py
@@ -1,11 +1,11 @@
 from __future__ import annotations
 
-from typing import Any, Dict
+from typing import Any
 
 from pkgmgr.actions.mirror.io import write_mirrors_file
 from pkgmgr.actions.mirror.setup_cmd import setup_mirrors
 
-Repository = Dict[str, Any]
+Repository = dict[str, Any]
 
 
 class MirrorBootstrapper:
diff --git a/src/pkgmgr/actions/repository/create/model.py b/src/pkgmgr/actions/repository/create/model.py
index 02911aa..258fcdf 100644
--- a/src/pkgmgr/actions/repository/create/model.py
+++ b/src/pkgmgr/actions/repository/create/model.py
@@ -1,12 +1,11 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
-from typing import Optional
 
 
 @dataclass(frozen=True)
 class RepoParts:
     host: str
-    port: Optional[str]
+    port: str | None
     owner: str
     name: str
diff --git a/src/pkgmgr/actions/repository/create/parser.py b/src/pkgmgr/actions/repository/create/parser.py
index e347e2b..7ab3180 100644
--- a/src/pkgmgr/actions/repository/create/parser.py
+++ b/src/pkgmgr/actions/repository/create/parser.py
@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 import re
-from typing import Tuple
 from urllib.parse import urlparse
 
 from .model import RepoParts
@@ -50,7 +49,7 @@ def _parse_git_url(url: str) -> RepoParts:
     return RepoParts(host=host, port=port, owner=owner, name=name)
 
 
-def _split_host_port(host: str) -> Tuple[str, str | None]:
+def _split_host_port(host: str) -> tuple[str, str | None]:
     if ":" in host:
         h, p = host.split(":", 1)
         return h, p or None
diff --git a/src/pkgmgr/actions/repository/create/planner.py b/src/pkgmgr/actions/repository/create/planner.py
index ca43cde..2bcc944 100644
--- a/src/pkgmgr/actions/repository/create/planner.py
+++ b/src/pkgmgr/actions/repository/create/planner.py
@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 import os
-from typing import Any, Dict
+from typing import Any
 
 from .model import RepoParts
 
@@ -38,7 +38,7 @@ class CreateRepoPlanner:
         *,
         author_name: str,
         author_email: str,
-    ) -> Dict[str, Any]:
+    ) -> dict[str, Any]:
         return {
             "provider": self.parts.host,
             "port": self.parts.port,
diff --git a/src/pkgmgr/actions/repository/create/service.py b/src/pkgmgr/actions/repository/create/service.py
index 4a8e754..062d221 100644
--- a/src/pkgmgr/actions/repository/create/service.py
+++ b/src/pkgmgr/actions/repository/create/service.py
@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 import os
-from typing import Any, Dict
+from typing import Any
 
 from pkgmgr.core.git.queries import get_config_value
 
@@ -17,7 +17,7 @@ class CreateRepoService:
     def __init__(
         self,
         *,
-        config_merged: Dict[str, Any],
+        config_merged: dict[str, Any],
         user_config_path: str,
         bin_dir: str,
     ):
diff --git a/src/pkgmgr/actions/repository/create/templates.py b/src/pkgmgr/actions/repository/create/templates.py
index ac849f1..e7e409b 100644
--- a/src/pkgmgr/actions/repository/create/templates.py
+++ b/src/pkgmgr/actions/repository/create/templates.py
@@ -25,7 +25,7 @@ class TemplateRenderer:
         self,
         *,
         repo_dir: str,
-        context: Dict[str, Any],
+        context: dict[str, Any],
         preview: bool,
     ) -> None:
         if preview:
diff --git a/src/pkgmgr/actions/repository/list.py b/src/pkgmgr/actions/repository/list.py
index 7b42ff9..ff72ed5 100644
--- a/src/pkgmgr/actions/repository/list.py
+++ b/src/pkgmgr/actions/repository/list.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 Pretty-print repository list with status, categories, tags and path.
 
@@ -15,9 +13,9 @@ from __future__ import annotations
 import os
 import re
 from textwrap import wrap
-from typing import Any, Dict, List, Optional
+from typing import Any
 
-Repository = Dict[str, Any]
+Repository = dict[str, Any]
 
 RESET = "\033[0m"
 BOLD = "\033[1m"
@@ -29,7 +27,7 @@ MAGENTA = "\033[35m"
 GREY = "\033[90m"
 
 
-def _compile_maybe_regex(pattern: str) -> Optional[re.Pattern[str]]:
+def _compile_maybe_regex(pattern: str) -> re.Pattern[str] | None:
     """
     If pattern is of the form /.../, return a compiled regex (case-insensitive).
     Otherwise return None.
@@ -88,7 +86,7 @@ def _compute_status(
     """
     Compute a human-readable status string, e.g. 'present,alias,ignored'.
     """
-    parts: List[str] = []
+    parts: list[str] = []
 
     exists = os.path.isdir(repo_dir)
     if exists:
@@ -128,7 +126,7 @@ def _color_status(status_padded: str) -> str:
     pad_spaces = len(status_padded) - len(core)
 
     plain_parts = core.split(",") if core else []
-    colored_parts: List[str] = []
+    colored_parts: list[str] = []
 
     for raw_part in plain_parts:
         name = raw_part.strip()
@@ -156,12 +154,12 @@ def _color_status(status_padded: str) -> str:
 
 
 def list_repositories(
-    repositories: List[Repository],
+    repositories: list[Repository],
     repositories_base_dir: str,
     binaries_dir: str,
     search_filter: str = "",
     status_filter: str = "",
-    extra_tags: Optional[List[str]] = None,
+    extra_tags: list[str] | None = None,
     show_description: bool = False,
 ) -> None:
     """
@@ -188,7 +186,7 @@ def list_repositories(
         extra_tags = []
 
     search_regex = _compile_maybe_regex(search_filter)
-    rows: List[Dict[str, Any]] = []
+    rows: list[dict[str, Any]] = []
 
     # ------------------------------------------------------------------
     # Build rows
@@ -208,17 +206,7 @@ def list_repositories(
             continue
 
         if search_filter:
-            haystack = " ".join(
-                [
-                    identifier,
-                    alias,
-                    provider,
-                    account,
-                    description,
-                    homepage,
-                    repo_dir,
-                ]
-            )
+            haystack = f"{identifier} {alias} {provider} {account} {description} {homepage} {repo_dir}"
             if search_regex:
                 if not search_regex.search(haystack):
                     continue
@@ -226,13 +214,13 @@ def list_repositories(
                 if search_filter.lower() not in haystack.lower():
                     continue
 
-        categories: List[str] = []
+        categories: list[str] = []
         categories.extend(map(str, repo.get("category_files", [])))
         if repo.get("category"):
             categories.append(str(repo["category"]))
 
-        yaml_tags: List[str] = list(map(str, repo.get("tags", [])))
-        display_tags: List[str] = sorted(set(yaml_tags + list(map(str, extra_tags))))
+        yaml_tags: list[str] = list(map(str, repo.get("tags", [])))
+        display_tags: list[str] = sorted(set(yaml_tags + list(map(str, extra_tags))))
 
         rows.append(
             {
diff --git a/src/pkgmgr/actions/repository/pull.py b/src/pkgmgr/actions/repository/pull.py
index 3983088..d66db30 100644
--- a/src/pkgmgr/actions/repository/pull.py
+++ b/src/pkgmgr/actions/repository/pull.py
@@ -2,7 +2,7 @@ from __future__ import annotations
 
 import os
 from concurrent.futures import ThreadPoolExecutor
-from typing import Any, Dict, List, Tuple
+from typing import Any
 
 from pkgmgr.actions.repository._parallel import RepoRef, run_on_repos
 from pkgmgr.core.git.commands import GitPullArgsError, pull_args
@@ -10,10 +10,10 @@ from pkgmgr.core.repository.dir import get_repo_dir
 from pkgmgr.core.repository.identifier import get_repo_identifier
 from pkgmgr.core.repository.verify import verify_repository
 
-Repository = Dict[str, Any]
+Repository = dict[str, Any]
 
 
-def _pull_one(repo_dir: str, extra_args: List[str], preview: bool) -> Tuple[bool, str]:
+def _pull_one(repo_dir: str, extra_args: list[str], preview: bool) -> tuple[bool, str]:
     try:
         pull_args(extra_args, cwd=repo_dir, preview=preview)
         return (True, "")
@@ -25,7 +25,7 @@ def _verify_one(
     repo: Repository,
     repo_dir: str,
     no_verification: bool,
-) -> Tuple[bool, bool, List[str]]:
+) -> tuple[bool, bool, list[str]]:
     """Returns (has_verified_info, verified_ok, errors)."""
     verified_ok, errors, _commit, _key = verify_repository(
         repo,
@@ -37,10 +37,10 @@ def _verify_one(
 
 
 def _verify_all(
-    candidates: List[Tuple[Repository, str, str]],
+    candidates: list[tuple[Repository, str, str]],
     no_verification: bool,
     jobs: int,
-) -> List[Tuple[str, str, bool, bool, List[str]]]:
+) -> list[tuple[str, str, bool, bool, list[str]]]:
     """
     Verify all candidates (parallel if ``jobs > 1``), preserving input order.
 
@@ -63,10 +63,10 @@ def _verify_all(
 
 
 def pull_with_verification(
-    selected_repos: List[Repository],
+    selected_repos: list[Repository],
     repositories_base_dir: str,
-    all_repos: List[Repository],
-    extra_args: List[str],
+    all_repos: list[Repository],
+    extra_args: list[str],
     no_verification: bool,
     preview: bool,
     jobs: int = 1,
@@ -80,7 +80,7 @@ def pull_with_verification(
     - Approved repos are then pulled in parallel when ``jobs > 1``.
     - On any pull failure, prints a summary and exits with status 1.
     """
-    candidates: List[Tuple[Repository, str, str]] = []
+    candidates: list[tuple[Repository, str, str]] = []
     for repo in selected_repos:
         ident = get_repo_identifier(repo, all_repos)
         rd = get_repo_dir(repositories_base_dir, repo)
@@ -94,7 +94,7 @@ def pull_with_verification(
 
     verify_results = _verify_all(candidates, no_verification, jobs)
 
-    approved: List[RepoRef] = []
+    approved: list[RepoRef] = []
     for ident, rd, has_verified_info, verified_ok, errors in verify_results:
         if (
             not preview
diff --git a/src/pkgmgr/actions/repository/push.py b/src/pkgmgr/actions/repository/push.py
index f80dbc0..db645ce 100644
--- a/src/pkgmgr/actions/repository/push.py
+++ b/src/pkgmgr/actions/repository/push.py
@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import Any, Dict, List, Tuple
+from typing import Any
 
 from pkgmgr.actions.repository._parallel import (
     resolve_repos,
@@ -8,10 +8,10 @@ from pkgmgr.actions.repository._parallel import (
 )
 from pkgmgr.core.git.commands import GitPushArgsError, push_args
 
-Repository = Dict[str, Any]
+Repository = dict[str, Any]
 
 
-def _push_one(repo_dir: str, extra_args: List[str], preview: bool) -> Tuple[bool, str]:
+def _push_one(repo_dir: str, extra_args: list[str], preview: bool) -> tuple[bool, str]:
     try:
         push_args(extra_args, cwd=repo_dir, preview=preview)
         return (True, "")
@@ -20,10 +20,10 @@ def _push_one(repo_dir: str, extra_args: List[str], preview: bool) -> Tuple[bool
 
 
 def push_in_parallel(
-    selected_repos: List[Repository],
+    selected_repos: list[Repository],
     repositories_base_dir: str,
-    all_repos: List[Repository],
-    extra_args: List[str],
+    all_repos: list[Repository],
+    extra_args: list[str],
     preview: bool,
     jobs: int = 1,
 ) -> None:
diff --git a/src/pkgmgr/actions/update/__init__.py b/src/pkgmgr/actions/update/__init__.py
index e91f6d8..ace9e0e 100644
--- a/src/pkgmgr/actions/update/__init__.py
+++ b/src/pkgmgr/actions/update/__init__.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 from pkgmgr.actions.update.manager import UpdateManager
diff --git a/src/pkgmgr/actions/update/manager.py b/src/pkgmgr/actions/update/manager.py
index 5bc504e..cda49dc 100644
--- a/src/pkgmgr/actions/update/manager.py
+++ b/src/pkgmgr/actions/update/manager.py
@@ -1,9 +1,7 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 from collections.abc import Iterable
-from typing import Any, List, Tuple
+from typing import Any
 
 from pkgmgr.actions.update.system_updater import SystemUpdater
 
@@ -37,7 +35,7 @@ class UpdateManager:
         from pkgmgr.actions.repository.pull import pull_with_verification
         from pkgmgr.core.repository.identifier import get_repo_identifier
 
-        failures: List[Tuple[str, str]] = []
+        failures: list[tuple[str, str]] = []
 
         for repo in list(selected_repos):
             identifier = get_repo_identifier(repo, all_repos)
diff --git a/src/pkgmgr/actions/update/os_release.py b/src/pkgmgr/actions/update/os_release.py
index 641caff..7a8b7e6 100644
--- a/src/pkgmgr/actions/update/os_release.py
+++ b/src/pkgmgr/actions/update/os_release.py
@@ -1,21 +1,18 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 import os
 from dataclasses import dataclass
-from typing import Dict
 
 
-def read_os_release(path: str = "/etc/os-release") -> Dict[str, str]:
+def read_os_release(path: str = "/etc/os-release") -> dict[str, str]:
     """
     Parse /etc/os-release into a dict. Returns empty dict if missing.
     """
     if not os.path.exists(path):
         return {}
 
-    result: Dict[str, str] = {}
-    with open(path, "r", encoding="utf-8") as f:
+    result: dict[str, str] = {}
+    with open(path, encoding="utf-8") as f:
         for line in f:
             line = line.strip()
             if not line or line.startswith("#") or "=" not in line:
diff --git a/src/pkgmgr/actions/update/system_updater.py b/src/pkgmgr/actions/update/system_updater.py
index a2a5363..45a6bf3 100644
--- a/src/pkgmgr/actions/update/system_updater.py
+++ b/src/pkgmgr/actions/update/system_updater.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 import platform
diff --git a/src/pkgmgr/cli/commands/changelog.py b/src/pkgmgr/cli/commands/changelog.py
index 8f97356..acc3b84 100644
--- a/src/pkgmgr/cli/commands/changelog.py
+++ b/src/pkgmgr/cli/commands/changelog.py
@@ -64,7 +64,7 @@ def _find_previous_and_current_tag(
 def handle_changelog(
     args,
     ctx: CLIContext,
-    selected: List[Repository],
+    selected: list[Repository],
 ) -> None:
     """
     Handle the 'changelog' command.
diff --git a/src/pkgmgr/cli/commands/config.py b/src/pkgmgr/cli/commands/config.py
index 462416e..289a5e0 100644
--- a/src/pkgmgr/cli/commands/config.py
+++ b/src/pkgmgr/cli/commands/config.py
@@ -1,6 +1,4 @@
 # src/pkgmgr/cli/commands/config.py
-#!/usr/bin/env python3
-# -*- coding: utf-8 -*-
 
 from __future__ import annotations
 
@@ -8,7 +6,7 @@ import os
 import shutil
 import sys
 from pathlib import Path
-from typing import Any, Dict, Optional
+from typing import Any
 
 import yaml
 
@@ -21,7 +19,7 @@ from pkgmgr.core.config.save import save_user_config
 from pkgmgr.core.repository.resolve import resolve_repos
 
 
-def _load_user_config(user_config_path: str) -> Dict[str, Any]:
+def _load_user_config(user_config_path: str) -> dict[str, Any]:
     """
     Load the user config from ~/.config/pkgmgr/config.yaml
     (or whatever ctx.user_config_path is), creating the directory if needed.
@@ -32,12 +30,12 @@ def _load_user_config(user_config_path: str) -> Dict[str, Any]:
         os.makedirs(cfg_dir, exist_ok=True)
 
     if os.path.exists(user_config_path_expanded):
-        with open(user_config_path_expanded, "r", encoding="utf-8") as f:
+        with open(user_config_path_expanded, encoding="utf-8") as f:
             return yaml.safe_load(f) or {"repositories": []}
     return {"repositories": []}
 
 
-def _find_defaults_source_dir() -> Optional[str]:
+def _find_defaults_source_dir() -> str | None:
     """
     Find the directory inside the installed pkgmgr package that contains
     the default config files.
@@ -75,7 +73,7 @@ def _update_default_configs(user_config_path: str) -> None:
 
     for name in os.listdir(source_dir):
         lower = name.lower()
-        if not (lower.endswith(".yml") or lower.endswith(".yaml")):
+        if not (lower.endswith((".yml", ".yaml"))):
             continue
         if name == "config.yaml":
             continue
diff --git a/src/pkgmgr/cli/commands/make.py b/src/pkgmgr/cli/commands/make.py
index cf7c399..b8e163c 100644
--- a/src/pkgmgr/cli/commands/make.py
+++ b/src/pkgmgr/cli/commands/make.py
@@ -1,18 +1,18 @@
 from __future__ import annotations
 
 import sys
-from typing import Any, Dict, List
+from typing import Any
 
 from pkgmgr.actions.proxy import exec_proxy_command
 from pkgmgr.cli.context import CLIContext
 
-Repository = Dict[str, Any]
+Repository = dict[str, Any]
 
 
 def handle_make(
     args,
     ctx: CLIContext,
-    selected: List[Repository],
+    selected: list[Repository],
 ) -> None:
     """
     Handle the 'make' command by delegating to exec_proxy_command.
diff --git a/src/pkgmgr/cli/commands/mirror.py b/src/pkgmgr/cli/commands/mirror.py
index e341e17..31ec5fe 100644
--- a/src/pkgmgr/cli/commands/mirror.py
+++ b/src/pkgmgr/cli/commands/mirror.py
@@ -2,7 +2,7 @@
 from __future__ import annotations
 
 import sys
-from typing import Any, Dict, List
+from typing import Any
 
 from pkgmgr.actions.mirror import (
     diff_mirrors,
@@ -13,13 +13,13 @@ from pkgmgr.actions.mirror import (
 )
 from pkgmgr.cli.context import CLIContext
 
-Repository = Dict[str, Any]
+Repository = dict[str, Any]
 
 
 def handle_mirror_command(
     ctx: CLIContext,
     args: Any,
-    selected: List[Repository],
+    selected: list[Repository],
 ) -> None:
     """
     Entry point for 'pkgmgr mirror' subcommands.
diff --git a/src/pkgmgr/cli/commands/publish.py b/src/pkgmgr/cli/commands/publish.py
index d3f0203..5848f6b 100644
--- a/src/pkgmgr/cli/commands/publish.py
+++ b/src/pkgmgr/cli/commands/publish.py
@@ -1,17 +1,17 @@
 from __future__ import annotations
 
 import os
-from typing import Any, Dict, List
+from typing import Any
 
 from pkgmgr.actions.publish import publish
 from pkgmgr.cli.context import CLIContext
 from pkgmgr.core.repository.dir import get_repo_dir
 from pkgmgr.core.repository.identifier import get_repo_identifier
 
-Repository = Dict[str, Any]
+Repository = dict[str, Any]
 
 
-def handle_publish(args, ctx: CLIContext, selected: List[Repository]) -> None:
+def handle_publish(args, ctx: CLIContext, selected: list[Repository]) -> None:
     if not selected:
         print("[pkgmgr] No repositories selected for publish.")
         return
diff --git a/src/pkgmgr/cli/commands/release.py b/src/pkgmgr/cli/commands/release.py
index 29d915e..4b3daab 100644
--- a/src/pkgmgr/cli/commands/release.py
+++ b/src/pkgmgr/cli/commands/release.py
@@ -1,10 +1,8 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 import os
 import sys
-from typing import Any, Dict, List
+from typing import Any
 
 from pkgmgr.actions.publish import publish as run_publish
 from pkgmgr.actions.release import release as run_release
@@ -12,13 +10,13 @@ from pkgmgr.cli.context import CLIContext
 from pkgmgr.core.repository.dir import get_repo_dir
 from pkgmgr.core.repository.identifier import get_repo_identifier
 
-Repository = Dict[str, Any]
+Repository = dict[str, Any]
 
 
 def handle_release(
     args,
     ctx: CLIContext,
-    selected: List[Repository],
+    selected: list[Repository],
 ) -> None:
     if not selected:
         print("[pkgmgr] No repositories selected for release.")
diff --git a/src/pkgmgr/cli/commands/repos.py b/src/pkgmgr/cli/commands/repos.py
index ea248de..e522d05 100644
--- a/src/pkgmgr/cli/commands/repos.py
+++ b/src/pkgmgr/cli/commands/repos.py
@@ -1,9 +1,7 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 import sys
-from typing import Any, Dict, List
+from typing import Any
 
 from pkgmgr.actions.install import install_repos
 from pkgmgr.actions.repository.create import create_repo
@@ -15,7 +13,7 @@ from pkgmgr.cli.context import CLIContext
 from pkgmgr.core.command.run import run_command
 from pkgmgr.core.repository.dir import get_repo_dir
 
-Repository = Dict[str, Any]
+Repository = dict[str, Any]
 
 
 def _resolve_repository_directory(repository: Repository, ctx: CLIContext) -> str:
@@ -45,7 +43,7 @@ def _resolve_repository_directory(repository: Repository, ctx: CLIContext) -> st
 def handle_repos_command(
     args,
     ctx: CLIContext,
-    selected: List[Repository],
+    selected: list[Repository],
 ) -> None:
     """
     Handle core repository commands (install/update/deinstall/delete/status/list/path/shell/create).
diff --git a/src/pkgmgr/cli/commands/tools.py b/src/pkgmgr/cli/commands/tools.py
index c81620a..ee55925 100644
--- a/src/pkgmgr/cli/commands/tools.py
+++ b/src/pkgmgr/cli/commands/tools.py
@@ -1,19 +1,19 @@
 from __future__ import annotations
 
-from typing import Any, Dict, List
+from typing import Any
 
 from pkgmgr.cli.context import CLIContext
 from pkgmgr.cli.tools import open_vscode_workspace
 from pkgmgr.cli.tools.paths import resolve_repository_path
 from pkgmgr.core.command.run import run_command
 
-Repository = Dict[str, Any]
+Repository = dict[str, Any]
 
 
 def handle_tools_command(
     args,
     ctx: CLIContext,
-    selected: List[Repository],
+    selected: list[Repository],
 ) -> None:
     # ------------------------------------------------------------------
     # nautilus "explore" command
diff --git a/src/pkgmgr/cli/commands/version.py b/src/pkgmgr/cli/commands/version.py
index d86bc8d..f8778dc 100644
--- a/src/pkgmgr/cli/commands/version.py
+++ b/src/pkgmgr/cli/commands/version.py
@@ -23,7 +23,7 @@ from pkgmgr.core.version.source import (
     read_spec_version,
 )
 
-Repository = Dict[str, Any]
+Repository = dict[str, Any]
 
 
 def _print_pkgmgr_self_version() -> None:
@@ -74,7 +74,7 @@ def _print_pkgmgr_self_version() -> None:
 def handle_version(
     args,
     ctx: CLIContext,
-    selected: List[Repository],
+    selected: list[Repository],
 ) -> None:
     """
     Handle the 'version' command.
diff --git a/src/pkgmgr/cli/context.py b/src/pkgmgr/cli/context.py
index ae64aab..ea56074 100644
--- a/src/pkgmgr/cli/context.py
+++ b/src/pkgmgr/cli/context.py
@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
-from typing import Any, Dict, List
+from typing import Any
 
 
 @dataclass
@@ -13,8 +13,8 @@ class CLIContext:
     keeps the CLI layer thin and structured.
     """
 
-    config_merged: Dict[str, Any]
+    config_merged: dict[str, Any]
     repositories_base_dir: str
-    all_repositories: List[Dict[str, Any]]
+    all_repositories: list[dict[str, Any]]
     binaries_dir: str
     user_config_path: str
diff --git a/src/pkgmgr/cli/dispatch.py b/src/pkgmgr/cli/dispatch.py
index db7f305..fd93f51 100644
--- a/src/pkgmgr/cli/dispatch.py
+++ b/src/pkgmgr/cli/dispatch.py
@@ -2,7 +2,7 @@ from __future__ import annotations
 
 import os
 import sys
-from typing import Any, Dict, List
+from typing import Any
 
 from pkgmgr.cli.commands import (
     handle_archive,
@@ -34,7 +34,7 @@ def _has_explicit_selection(args) -> bool:
     )
 
 
-def _select_repo_for_current_directory(ctx: CLIContext) -> List[Dict[str, Any]]:
+def _select_repo_for_current_directory(ctx: CLIContext) -> list[dict[str, Any]]:
     cwd = os.path.abspath(os.getcwd())
     matches = []
 
diff --git a/src/pkgmgr/cli/parser/branch_cmd.py b/src/pkgmgr/cli/parser/branch_cmd.py
index d31545f..44709ac 100644
--- a/src/pkgmgr/cli/parser/branch_cmd.py
+++ b/src/pkgmgr/cli/parser/branch_cmd.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 import argparse
diff --git a/src/pkgmgr/cli/parser/changelog_cmd.py b/src/pkgmgr/cli/parser/changelog_cmd.py
index 8896f22..35c760b 100644
--- a/src/pkgmgr/cli/parser/changelog_cmd.py
+++ b/src/pkgmgr/cli/parser/changelog_cmd.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 import argparse
diff --git a/src/pkgmgr/cli/parser/common.py b/src/pkgmgr/cli/parser/common.py
index 2255ed1..5f11a7a 100644
--- a/src/pkgmgr/cli/parser/common.py
+++ b/src/pkgmgr/cli/parser/common.py
@@ -2,7 +2,6 @@
 from __future__ import annotations
 
 import argparse
-from typing import Optional, Tuple
 
 
 class SortedSubParsersAction(argparse._SubParsersAction):
@@ -19,8 +18,8 @@ class SortedSubParsersAction(argparse._SubParsersAction):
 def _has_action(
     parser: argparse.ArgumentParser,
     *,
-    positional: Optional[str] = None,
-    options: Tuple[str, ...] = (),
+    positional: str | None = None,
+    options: tuple[str, ...] = (),
 ) -> bool:
     """
     Check whether the parser already has an action.
diff --git a/src/pkgmgr/cli/parser/config_cmd.py b/src/pkgmgr/cli/parser/config_cmd.py
index 7d48c74..4b3f102 100644
--- a/src/pkgmgr/cli/parser/config_cmd.py
+++ b/src/pkgmgr/cli/parser/config_cmd.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 import argparse
diff --git a/src/pkgmgr/cli/parser/install_update.py b/src/pkgmgr/cli/parser/install_update.py
index b2d7897..f0696cd 100644
--- a/src/pkgmgr/cli/parser/install_update.py
+++ b/src/pkgmgr/cli/parser/install_update.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 import argparse
 
 from pkgmgr.cli.parser.common import (
diff --git a/src/pkgmgr/cli/parser/list_cmd.py b/src/pkgmgr/cli/parser/list_cmd.py
index 7eaead5..b6332b5 100644
--- a/src/pkgmgr/cli/parser/list_cmd.py
+++ b/src/pkgmgr/cli/parser/list_cmd.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 import argparse
diff --git a/src/pkgmgr/cli/parser/make_cmd.py b/src/pkgmgr/cli/parser/make_cmd.py
index 661b4b9..9fc9d82 100644
--- a/src/pkgmgr/cli/parser/make_cmd.py
+++ b/src/pkgmgr/cli/parser/make_cmd.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 import argparse
diff --git a/src/pkgmgr/cli/parser/mirror_cmd.py b/src/pkgmgr/cli/parser/mirror_cmd.py
index 2287afa..d4a8bf6 100644
--- a/src/pkgmgr/cli/parser/mirror_cmd.py
+++ b/src/pkgmgr/cli/parser/mirror_cmd.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 import argparse
diff --git a/src/pkgmgr/cli/parser/navigation_cmd.py b/src/pkgmgr/cli/parser/navigation_cmd.py
index 4bca222..cd1ca79 100644
--- a/src/pkgmgr/cli/parser/navigation_cmd.py
+++ b/src/pkgmgr/cli/parser/navigation_cmd.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 import argparse
diff --git a/src/pkgmgr/cli/parser/release_cmd.py b/src/pkgmgr/cli/parser/release_cmd.py
index 5f84078..a806b67 100644
--- a/src/pkgmgr/cli/parser/release_cmd.py
+++ b/src/pkgmgr/cli/parser/release_cmd.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 import argparse
diff --git a/src/pkgmgr/cli/parser/version_cmd.py b/src/pkgmgr/cli/parser/version_cmd.py
index 267c12a..e9eb743 100644
--- a/src/pkgmgr/cli/parser/version_cmd.py
+++ b/src/pkgmgr/cli/parser/version_cmd.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 import argparse
diff --git a/src/pkgmgr/cli/proxy.py b/src/pkgmgr/cli/proxy.py
index e219a72..2df33bf 100644
--- a/src/pkgmgr/cli/proxy.py
+++ b/src/pkgmgr/cli/proxy.py
@@ -1,11 +1,9 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 import argparse
 import os
 import sys
-from typing import Any, Dict, List
+from typing import Any
 
 from pkgmgr.actions.proxy import exec_proxy_command
 from pkgmgr.actions.repository.clone import clone_repos
@@ -15,7 +13,7 @@ from pkgmgr.cli.context import CLIContext
 from pkgmgr.core.repository.dir import get_repo_dir
 from pkgmgr.core.repository.selected import get_selected_repos
 
-PROXY_COMMANDS: Dict[str, List[str]] = {
+PROXY_COMMANDS: dict[str, list[str]] = {
     "git": [
         "pull",
         "push",
diff --git a/src/pkgmgr/cli/tools/paths.py b/src/pkgmgr/cli/tools/paths.py
index 174e371..198a4ea 100644
--- a/src/pkgmgr/cli/tools/paths.py
+++ b/src/pkgmgr/cli/tools/paths.py
@@ -1,11 +1,11 @@
 from __future__ import annotations
 
-from typing import Any, Dict
+from typing import Any
 
 from pkgmgr.cli.context import CLIContext
 from pkgmgr.core.repository.dir import get_repo_dir
 
-Repository = Dict[str, Any]
+Repository = dict[str, Any]
 
 
 def resolve_repository_path(repository: Repository, ctx: CLIContext) -> str:
diff --git a/src/pkgmgr/cli/tools/vscode.py b/src/pkgmgr/cli/tools/vscode.py
index 2f0065d..01cffca 100644
--- a/src/pkgmgr/cli/tools/vscode.py
+++ b/src/pkgmgr/cli/tools/vscode.py
@@ -3,14 +3,14 @@ from __future__ import annotations
 import json
 import os
 import shutil
-from typing import Any, Dict, List
+from typing import Any
 
 from pkgmgr.cli.context import CLIContext
 from pkgmgr.cli.tools.paths import resolve_repository_path
 from pkgmgr.core.command.run import run_command
 from pkgmgr.core.repository.identifier import get_repo_identifier
 
-Repository = Dict[str, Any]
+Repository = dict[str, Any]
 
 
 def _ensure_vscode_cli_available() -> None:
@@ -26,7 +26,7 @@ def _ensure_vscode_cli_available() -> None:
         )
 
 
-def _ensure_identifiers_are_filename_safe(identifiers: List[str]) -> None:
+def _ensure_identifiers_are_filename_safe(identifiers: list[str]) -> None:
     """
     Ensure identifiers can be used in a filename.
 
@@ -52,14 +52,14 @@ def _resolve_workspaces_dir(ctx: CLIContext) -> str:
     return os.path.expanduser(directories_cfg.get("workspaces", "~/Workspaces"))
 
 
-def _build_workspace_filename(identifiers: List[str]) -> str:
+def _build_workspace_filename(identifiers: list[str]) -> str:
     sorted_identifiers = sorted(identifiers)
     return "_".join(sorted_identifiers) + ".code-workspace"
 
 
 def _build_workspace_data(
-    selected: List[Repository], ctx: CLIContext
-) -> Dict[str, Any]:
+    selected: list[Repository], ctx: CLIContext
+) -> dict[str, Any]:
     folders = [{"path": resolve_repository_path(repo, ctx)} for repo in selected]
     return {
         "folders": folders,
@@ -67,7 +67,7 @@ def _build_workspace_data(
     }
 
 
-def open_vscode_workspace(ctx: CLIContext, selected: List[Repository]) -> None:
+def open_vscode_workspace(ctx: CLIContext, selected: list[Repository]) -> None:
     """
     Create (if missing) and open a VS Code workspace for the selected repositories.
 
diff --git a/src/pkgmgr/core/command/ink.py b/src/pkgmgr/core/command/ink.py
index 9d48178..3cc1b4b 100644
--- a/src/pkgmgr/core/command/ink.py
+++ b/src/pkgmgr/core/command/ink.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 import os
 
 from pkgmgr.core.repository.dir import get_repo_dir
diff --git a/src/pkgmgr/core/command/resolve.py b/src/pkgmgr/core/command/resolve.py
index 7bfb583..f837324 100644
--- a/src/pkgmgr/core/command/resolve.py
+++ b/src/pkgmgr/core/command/resolve.py
@@ -1,15 +1,17 @@
+from __future__ import annotations
+
 import os
 import shutil
-from typing import Any, Dict, List, Optional
+from typing import Any
 
-Repository = Dict[str, Any]
+Repository = dict[str, Any]
 
 
 def _is_executable(path: str) -> bool:
     return os.path.exists(path) and os.access(path, os.X_OK)
 
 
-def _find_python_package_root(repo_dir: str) -> Optional[str]:
+def _find_python_package_root(repo_dir: str) -> str | None:
     """
     Detect a Python src-layout package:
 
@@ -29,19 +31,19 @@ def _find_python_package_root(repo_dir: str) -> Optional[str]:
     return None
 
 
-def _nix_binary_candidates(home: str, names: List[str]) -> List[str]:
+def _nix_binary_candidates(home: str, names: list[str]) -> list[str]:
     """
     Build possible Nix profile binary paths for a list of candidate names.
     """
     return [os.path.join(home, ".nix-profile", "bin", name) for name in names if name]
 
 
-def _path_binary_candidates(names: List[str]) -> List[str]:
+def _path_binary_candidates(names: list[str]) -> list[str]:
     """
     Resolve candidate names via PATH using shutil.which.
     Returns only existing, executable paths.
     """
-    binaries: List[str] = []
+    binaries: list[str] = []
     for name in names:
         if not name:
             continue
@@ -55,7 +57,7 @@ def resolve_command_for_repo(
     repo: Repository,
     repo_identifier: str,
     repo_dir: str,
-) -> Optional[str]:
+) -> str | None:
     """
     Resolve the executable command for a repository.
 
@@ -110,7 +112,7 @@ def resolve_command_for_repo(
     else:
         python_package_name = None
 
-    candidate_names: List[str] = []
+    candidate_names: list[str] = []
     seen: set[str] = set()
 
     for name in (
@@ -130,8 +132,8 @@ def resolve_command_for_repo(
     path_binaries = _path_binary_candidates(candidate_names)
 
     # b) Classify system (/usr/...) vs non-system
-    system_binary: Optional[str] = None
-    non_system_binary: Optional[str] = None
+    system_binary: str | None = None
+    non_system_binary: str | None = None
 
     for bin_path in path_binaries:
         if bin_path.startswith("/usr"):
diff --git a/src/pkgmgr/core/command/run.py b/src/pkgmgr/core/command/run.py
index 9c7ec53..9786714 100644
--- a/src/pkgmgr/core/command/run.py
+++ b/src/pkgmgr/core/command/run.py
@@ -1,16 +1,17 @@
 from __future__ import annotations
 
+import contextlib
 import selectors
 import subprocess
 import sys
-from typing import List, Optional, Union
+from typing import Union
 
-CommandType = Union[str, List[str]]
+CommandType = Union[str, list[str]]
 
 
 def run_command(
     cmd: CommandType,
-    cwd: Optional[str] = None,
+    cwd: str | None = None,
     preview: bool = False,
     allow_failure: bool = False,
 ) -> subprocess.CompletedProcess:
@@ -48,8 +49,8 @@ def run_command(
     sel.register(process.stdout, selectors.EVENT_READ, data="stdout")
     sel.register(process.stderr, selectors.EVENT_READ, data="stderr")
 
-    stdout_lines: List[str] = []
-    stderr_lines: List[str] = []
+    stdout_lines: list[str] = []
+    stderr_lines: list[str] = []
 
     try:
         while sel.get_map():
diff --git a/src/pkgmgr/core/config/load.py b/src/pkgmgr/core/config/load.py
index dca19fc..62d4c04 100644
--- a/src/pkgmgr/core/config/load.py
+++ b/src/pkgmgr/core/config/load.py
@@ -1,6 +1,4 @@
 # src/pkgmgr/core/config/load.py
-#!/usr/bin/env python3
-# -*- coding: utf-8 -*-
 
 """
 Load and merge pkgmgr configuration.
@@ -38,11 +36,11 @@ from __future__ import annotations
 
 import os
 from pathlib import Path
-from typing import Any, Dict, List, Optional, Tuple
+from typing import Any
 
 import yaml
 
-Repo = Dict[str, Any]
+Repo = dict[str, Any]
 
 
 # ---------------------------------------------------------------------------
@@ -50,7 +48,7 @@ Repo = Dict[str, Any]
 # ---------------------------------------------------------------------------
 
 
-def _deep_merge(base: Dict[str, Any], override: Dict[str, Any]) -> Dict[str, Any]:
+def _deep_merge(base: dict[str, Any], override: dict[str, Any]) -> dict[str, Any]:
     """
     Recursively merge two dictionaries.
 
@@ -64,7 +62,7 @@ def _deep_merge(base: Dict[str, Any], override: Dict[str, Any]) -> Dict[str, Any
     return base
 
 
-def _repo_key(repo: Repo) -> Tuple[str, str, str]:
+def _repo_key(repo: Repo) -> tuple[str, str, str]:
     """
     Normalised key for identifying a repository across config files.
     """
@@ -76,10 +74,10 @@ def _repo_key(repo: Repo) -> Tuple[str, str, str]:
 
 
 def _merge_repo_lists(
-    base_list: List[Repo],
-    new_list: List[Repo],
-    category_name: Optional[str] = None,
-) -> List[Repo]:
+    base_list: list[Repo],
+    new_list: list[Repo],
+    category_name: str | None = None,
+) -> list[Repo]:
     """
     Merge two repository lists, matching by (provider, account, repository).
 
@@ -87,7 +85,7 @@ def _merge_repo_lists(
     - If it exists, its fields are deep-merged (override wins).
     - If category_name is set, it is appended to repo["category_files"].
     """
-    index: Dict[Tuple[str, str, str], Repo] = {_repo_key(r): r for r in base_list}
+    index: dict[tuple[str, str, str], Repo] = {_repo_key(r): r for r in base_list}
 
     for src in new_list:
         key = _repo_key(src)
@@ -120,7 +118,7 @@ def _merge_repo_lists(
     return base_list
 
 
-def _load_yaml_file(path: Path) -> Dict[str, Any]:
+def _load_yaml_file(path: Path) -> dict[str, Any]:
     """
     Load a single YAML file as dict. Non-dicts yield {}.
     """
@@ -135,8 +133,8 @@ def _load_yaml_file(path: Path) -> Dict[str, Any]:
 
 def _load_layer_dir(
     config_dir: Path,
-    skip_filename: Optional[str] = None,
-) -> Dict[str, Any]:
+    skip_filename: str | None = None,
+) -> dict[str, Any]:
     """
     Load all *.yml/*.yaml from a directory as layered defaults.
 
@@ -148,7 +146,7 @@ def _load_layer_dir(
         "repositories": [...],
       }
     """
-    defaults: Dict[str, Any] = {"directories": {}, "repositories": []}
+    defaults: dict[str, Any] = {"directories": {}, "repositories": []}
 
     if not config_dir.is_dir():
         return defaults
@@ -186,7 +184,7 @@ def _load_layer_dir(
     return defaults
 
 
-def _load_defaults_from_package_or_project() -> Dict[str, Any]:
+def _load_defaults_from_package_or_project() -> dict[str, Any]:
     """
     Fallback: load default configs from possible install or dev layouts.
 
@@ -224,7 +222,7 @@ def _load_defaults_from_package_or_project() -> Dict[str, Any]:
 # ---------------------------------------------------------------------------
 
 
-def load_config(user_config_path: str) -> Dict[str, Any]:
+def load_config(user_config_path: str) -> dict[str, Any]:
     """
     Load and merge configuration for pkgmgr.
 
@@ -258,14 +256,14 @@ def load_config(user_config_path: str) -> Dict[str, Any]:
     defaults.setdefault("repositories", [])
 
     # 4) User config
-    user_cfg: Dict[str, Any] = {}
+    user_cfg: dict[str, Any] = {}
     if user_cfg_path.is_file():
         user_cfg = _load_yaml_file(user_cfg_path)
     user_cfg.setdefault("directories", {})
     user_cfg.setdefault("repositories", [])
 
     # 5) Merge
-    merged: Dict[str, Any] = {}
+    merged: dict[str, Any] = {}
 
     merged["directories"] = {}
     _deep_merge(merged["directories"], defaults["directories"])
diff --git a/src/pkgmgr/core/credentials/providers/env.py b/src/pkgmgr/core/credentials/providers/env.py
index 7f2a8b8..9e0e852 100644
--- a/src/pkgmgr/core/credentials/providers/env.py
+++ b/src/pkgmgr/core/credentials/providers/env.py
@@ -3,7 +3,6 @@ from __future__ import annotations
 
 import os
 from dataclasses import dataclass
-from typing import Optional
 
 from ..store_keys import env_var_candidates
 from ..types import TokenRequest, TokenResult
@@ -15,7 +14,7 @@ class EnvTokenProvider:
 
     source_name: str = "env"
 
-    def get(self, request: TokenRequest) -> Optional[TokenResult]:
+    def get(self, request: TokenRequest) -> TokenResult | None:
         for key in env_var_candidates(
             request.provider_kind, request.host, request.owner
         ):
diff --git a/src/pkgmgr/core/credentials/providers/gh.py b/src/pkgmgr/core/credentials/providers/gh.py
index 7ad2973..7de4b27 100644
--- a/src/pkgmgr/core/credentials/providers/gh.py
+++ b/src/pkgmgr/core/credentials/providers/gh.py
@@ -3,7 +3,6 @@ from __future__ import annotations
 import shutil
 import subprocess
 from dataclasses import dataclass
-from typing import Optional
 
 from ..types import TokenRequest, TokenResult
 
@@ -18,7 +17,7 @@ class GhTokenProvider:
 
     source_name: str = "gh"
 
-    def get(self, request: TokenRequest) -> Optional[TokenResult]:
+    def get(self, request: TokenRequest) -> TokenResult | None:
         # Only meaningful for GitHub-like providers
         kind = (request.provider_kind or "").strip().lower()
         if kind not in ("github", "github.com"):
diff --git a/src/pkgmgr/core/credentials/providers/prompt.py b/src/pkgmgr/core/credentials/providers/prompt.py
index 4d03d6f..1268829 100644
--- a/src/pkgmgr/core/credentials/providers/prompt.py
+++ b/src/pkgmgr/core/credentials/providers/prompt.py
@@ -4,12 +4,11 @@ from __future__ import annotations
 import sys
 from dataclasses import dataclass
 from getpass import getpass
-from typing import Optional
 
 from ..types import TokenRequest, TokenResult
 
 
-def _token_help_url(provider_kind: str, host: str) -> Optional[str]:
+def _token_help_url(provider_kind: str, host: str) -> str | None:
     """
     Return a provider-specific URL where a user can create/get an API token.
 
@@ -51,7 +50,7 @@ class PromptTokenProvider:
 
     source_name: str = "prompt"
 
-    def get(self, request: TokenRequest) -> Optional[TokenResult]:
+    def get(self, request: TokenRequest) -> TokenResult | None:
         if not sys.stdin.isatty():
             return None
 
diff --git a/src/pkgmgr/core/credentials/store_keys.py b/src/pkgmgr/core/credentials/store_keys.py
index e0510c2..2c68354 100644
--- a/src/pkgmgr/core/credentials/store_keys.py
+++ b/src/pkgmgr/core/credentials/store_keys.py
@@ -2,7 +2,6 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
-from typing import Optional
 
 
 @dataclass(frozen=True)
@@ -14,7 +13,7 @@ class KeyringKey:
 
 
 def build_keyring_key(
-    provider_kind: str, host: str, owner: Optional[str]
+    provider_kind: str, host: str, owner: str | None
 ) -> KeyringKey:
     """Build a stable keyring key.
 
@@ -30,7 +29,7 @@ def build_keyring_key(
 
 
 def env_var_candidates(
-    provider_kind: str, host: str, owner: Optional[str]
+    provider_kind: str, host: str, owner: str | None
 ) -> list[str]:
     """Return a list of environment variable names to try.
 
diff --git a/src/pkgmgr/core/git/commands/add.py b/src/pkgmgr/core/git/commands/add.py
index 41e9be7..1860d26 100644
--- a/src/pkgmgr/core/git/commands/add.py
+++ b/src/pkgmgr/core/git/commands/add.py
@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 from collections.abc import Iterable, Sequence
-from typing import List, Union
+from typing import Union
 
 from ..errors import GitCommandError, GitRunError
 from ..run import run
@@ -14,7 +14,7 @@ class GitAddError(GitCommandError):
 PathLike = Union[str, Sequence[str], Iterable[str]]
 
 
-def _normalize_paths(paths: PathLike) -> List[str]:
+def _normalize_paths(paths: PathLike) -> list[str]:
     if isinstance(paths, str):
         return [paths]
     return [p for p in paths]
diff --git a/src/pkgmgr/core/git/commands/clone.py b/src/pkgmgr/core/git/commands/clone.py
index 434ada3..64d9c70 100644
--- a/src/pkgmgr/core/git/commands/clone.py
+++ b/src/pkgmgr/core/git/commands/clone.py
@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-from typing import List
-
 from ..errors import GitCommandError, GitRunError
 from ..run import run
 
@@ -11,7 +9,7 @@ class GitCloneError(GitCommandError):
 
 
 def clone(
-    args: List[str],
+    args: list[str],
     *,
     cwd: str = ".",
     preview: bool = False,
diff --git a/src/pkgmgr/core/git/commands/pull_args.py b/src/pkgmgr/core/git/commands/pull_args.py
index 374ab75..cb51947 100644
--- a/src/pkgmgr/core/git/commands/pull_args.py
+++ b/src/pkgmgr/core/git/commands/pull_args.py
@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-from typing import List
-
 from ..errors import GitCommandError, GitRunError
 from ..run import run
 
@@ -11,7 +9,7 @@ class GitPullArgsError(GitCommandError):
 
 
 def pull_args(
-    args: List[str] | None = None,
+    args: list[str] | None = None,
     *,
     cwd: str = ".",
     preview: bool = False,
diff --git a/src/pkgmgr/core/git/commands/push_args.py b/src/pkgmgr/core/git/commands/push_args.py
index c455482..fb36daa 100644
--- a/src/pkgmgr/core/git/commands/push_args.py
+++ b/src/pkgmgr/core/git/commands/push_args.py
@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-from typing import List
-
 from ..errors import GitCommandError, GitRunError
 from ..run import run
 
@@ -11,7 +9,7 @@ class GitPushArgsError(GitCommandError):
 
 
 def push_args(
-    args: List[str] | None = None,
+    args: list[str] | None = None,
     *,
     cwd: str = ".",
     preview: bool = False,
diff --git a/src/pkgmgr/core/git/queries/get_changelog.py b/src/pkgmgr/core/git/queries/get_changelog.py
index 750f96b..88ab5e0 100644
--- a/src/pkgmgr/core/git/queries/get_changelog.py
+++ b/src/pkgmgr/core/git/queries/get_changelog.py
@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-from typing import Optional
-
 from ..errors import GitQueryError, GitRunError
 from ..run import run
 
@@ -13,8 +11,8 @@ class GitChangelogQueryError(GitQueryError):
 def get_changelog(
     *,
     cwd: str,
-    from_ref: Optional[str] = None,
-    to_ref: Optional[str] = None,
+    from_ref: str | None = None,
+    to_ref: str | None = None,
     include_merges: bool = False,
 ) -> str:
     """
diff --git a/src/pkgmgr/core/git/queries/get_config_value.py b/src/pkgmgr/core/git/queries/get_config_value.py
index 3869c3b..118aaee 100644
--- a/src/pkgmgr/core/git/queries/get_config_value.py
+++ b/src/pkgmgr/core/git/queries/get_config_value.py
@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-from typing import Optional
-
 from ..errors import GitRunError
 from ..run import run
 
@@ -17,7 +15,7 @@ def _is_missing_key_error(exc: GitRunError) -> bool:
     return "exit code: 1" in msg
 
 
-def get_config_value(key: str, *, cwd: str = ".") -> Optional[str]:
+def get_config_value(key: str, *, cwd: str = ".") -> str | None:
     """
     Return a value from `git config --get <key>`, or None if not set.
 
diff --git a/src/pkgmgr/core/git/queries/get_current_branch.py b/src/pkgmgr/core/git/queries/get_current_branch.py
index b63b090..3d1f38c 100644
--- a/src/pkgmgr/core/git/queries/get_current_branch.py
+++ b/src/pkgmgr/core/git/queries/get_current_branch.py
@@ -1,12 +1,10 @@
 from __future__ import annotations
 
-from typing import Optional
-
 from ..errors import GitRunError
 from ..run import run
 
 
-def get_current_branch(cwd: str = ".") -> Optional[str]:
+def get_current_branch(cwd: str = ".") -> str | None:
     """
     Return the current branch name, or None if it cannot be determined.
 
diff --git a/src/pkgmgr/core/git/queries/get_head_commit.py b/src/pkgmgr/core/git/queries/get_head_commit.py
index 84d4117..11d98ee 100644
--- a/src/pkgmgr/core/git/queries/get_head_commit.py
+++ b/src/pkgmgr/core/git/queries/get_head_commit.py
@@ -1,12 +1,10 @@
 from __future__ import annotations
 
-from typing import Optional
-
 from ..errors import GitRunError
 from ..run import run
 
 
-def get_head_commit(cwd: str = ".") -> Optional[str]:
+def get_head_commit(cwd: str = ".") -> str | None:
     """
     Return the current HEAD commit hash, or None if it cannot be determined.
     """
diff --git a/src/pkgmgr/core/git/queries/get_latest_commit.py b/src/pkgmgr/core/git/queries/get_latest_commit.py
index a0a82c6..9cbef8f 100644
--- a/src/pkgmgr/core/git/queries/get_latest_commit.py
+++ b/src/pkgmgr/core/git/queries/get_latest_commit.py
@@ -1,12 +1,10 @@
 from __future__ import annotations
 
-from typing import Optional
-
 from ..errors import GitRunError
 from ..run import run
 
 
-def get_latest_commit(cwd: str = ".") -> Optional[str]:
+def get_latest_commit(cwd: str = ".") -> str | None:
     """
     Return the latest commit hash for the repository in `cwd`.
 
diff --git a/src/pkgmgr/core/git/queries/get_latest_signing_key.py b/src/pkgmgr/core/git/queries/get_latest_signing_key.py
index a99b7f0..c4bb681 100644
--- a/src/pkgmgr/core/git/queries/get_latest_signing_key.py
+++ b/src/pkgmgr/core/git/queries/get_latest_signing_key.py
@@ -43,8 +43,7 @@ def get_latest_signing_key(*, cwd: str = ".") -> str:
             cmd,
             cwd=cwd,
             check=False,
-            stdout=subprocess.PIPE,
-            stderr=subprocess.PIPE,
+            capture_output=True,
             text=True,
         )
     except OSError as exc:
diff --git a/src/pkgmgr/core/git/queries/get_remote_push_urls.py b/src/pkgmgr/core/git/queries/get_remote_push_urls.py
index 629ac47..e92e4e8 100644
--- a/src/pkgmgr/core/git/queries/get_remote_push_urls.py
+++ b/src/pkgmgr/core/git/queries/get_remote_push_urls.py
@@ -1,11 +1,9 @@
 from __future__ import annotations
 
-from typing import Set
-
 from ..run import run
 
 
-def get_remote_push_urls(remote: str, cwd: str = ".") -> Set[str]:
+def get_remote_push_urls(remote: str, cwd: str = ".") -> set[str]:
     """
     Return all push URLs configured for a remote.
 
diff --git a/src/pkgmgr/core/git/queries/get_repo_root.py b/src/pkgmgr/core/git/queries/get_repo_root.py
index 55ae311..d85bc74 100644
--- a/src/pkgmgr/core/git/queries/get_repo_root.py
+++ b/src/pkgmgr/core/git/queries/get_repo_root.py
@@ -1,12 +1,10 @@
 from __future__ import annotations
 
-from typing import Optional
-
 from ..errors import GitRunError
 from ..run import run
 
 
-def get_repo_root(*, cwd: str = ".") -> Optional[str]:
+def get_repo_root(*, cwd: str = ".") -> str | None:
     """
     Return the git repository root directory (top-level), or None if not available.
 
diff --git a/src/pkgmgr/core/git/queries/get_tags.py b/src/pkgmgr/core/git/queries/get_tags.py
index 4ebc19c..0a2c345 100644
--- a/src/pkgmgr/core/git/queries/get_tags.py
+++ b/src/pkgmgr/core/git/queries/get_tags.py
@@ -1,12 +1,10 @@
 from __future__ import annotations
 
-from typing import List
-
 from ..errors import GitRunError
 from ..run import run
 
 
-def get_tags(cwd: str = ".") -> List[str]:
+def get_tags(cwd: str = ".") -> list[str]:
     """
     Return a list of all tags in the repository in `cwd`.
 
diff --git a/src/pkgmgr/core/git/queries/get_tags_at_ref.py b/src/pkgmgr/core/git/queries/get_tags_at_ref.py
index 8ce74c7..916e57d 100644
--- a/src/pkgmgr/core/git/queries/get_tags_at_ref.py
+++ b/src/pkgmgr/core/git/queries/get_tags_at_ref.py
@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-from typing import List
-
 from ..errors import GitQueryError, GitRunError
 from ..run import run
 
@@ -10,7 +8,7 @@ class GitTagsAtRefQueryError(GitQueryError):
     """Raised when querying tags for a ref fails."""
 
 
-def get_tags_at_ref(ref: str, *, cwd: str = ".") -> List[str]:
+def get_tags_at_ref(ref: str, *, cwd: str = ".") -> list[str]:
     """
     Return all git tags pointing at a given ref.
 
diff --git a/src/pkgmgr/core/git/queries/get_upstream_ref.py b/src/pkgmgr/core/git/queries/get_upstream_ref.py
index ef6dd1d..81c3710 100644
--- a/src/pkgmgr/core/git/queries/get_upstream_ref.py
+++ b/src/pkgmgr/core/git/queries/get_upstream_ref.py
@@ -1,12 +1,10 @@
 from __future__ import annotations
 
-from typing import Optional
-
 from ..errors import GitRunError
 from ..run import run
 
 
-def get_upstream_ref(*, cwd: str = ".") -> Optional[str]:
+def get_upstream_ref(*, cwd: str = ".") -> str | None:
     """
     Return the configured upstream ref for the current branch, or None if none.
 
diff --git a/src/pkgmgr/core/git/queries/list_remotes.py b/src/pkgmgr/core/git/queries/list_remotes.py
index c982124..83ba7ec 100644
--- a/src/pkgmgr/core/git/queries/list_remotes.py
+++ b/src/pkgmgr/core/git/queries/list_remotes.py
@@ -1,11 +1,9 @@
 from __future__ import annotations
 
-from typing import List
-
 from ..run import run
 
 
-def list_remotes(cwd: str = ".") -> List[str]:
+def list_remotes(cwd: str = ".") -> list[str]:
     """
     Return a list of configured git remotes (e.g. ['origin', 'upstream']).
 
diff --git a/src/pkgmgr/core/git/queries/list_tags.py b/src/pkgmgr/core/git/queries/list_tags.py
index 8d57c9d..2cf34e4 100644
--- a/src/pkgmgr/core/git/queries/list_tags.py
+++ b/src/pkgmgr/core/git/queries/list_tags.py
@@ -1,11 +1,9 @@
 from __future__ import annotations
 
-from typing import List
-
 from ..run import run
 
 
-def list_tags(pattern: str = "*", *, cwd: str = ".") -> List[str]:
+def list_tags(pattern: str = "*", *, cwd: str = ".") -> list[str]:
     """
     List tags matching a pattern.
 
diff --git a/src/pkgmgr/core/git/queries/probe_remote_reachable.py b/src/pkgmgr/core/git/queries/probe_remote_reachable.py
index 350a0d2..56a6509 100644
--- a/src/pkgmgr/core/git/queries/probe_remote_reachable.py
+++ b/src/pkgmgr/core/git/queries/probe_remote_reachable.py
@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-from typing import Tuple
-
 from ..errors import GitRunError
 from ..run import run
 
@@ -91,7 +89,7 @@ def _format_reason(exc: GitRunError, *, url: str) -> str:
     return reason.strip()
 
 
-def probe_remote_reachable_detail(url: str, cwd: str = ".") -> Tuple[bool, str]:
+def probe_remote_reachable_detail(url: str, cwd: str = ".") -> tuple[bool, str]:
     """
     Probe whether a remote URL is reachable.
 
diff --git a/src/pkgmgr/core/git/run.py b/src/pkgmgr/core/git/run.py
index 9c93682..a0d5d2c 100644
--- a/src/pkgmgr/core/git/run.py
+++ b/src/pkgmgr/core/git/run.py
@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 import subprocess
-from typing import List
 
 from .errors import GitNotRepositoryError, GitRunError
 
@@ -12,7 +11,7 @@ def _is_not_repo_error(stderr: str) -> bool:
 
 
 def run(
-    args: List[str],
+    args: list[str],
     *,
     cwd: str = ".",
     preview: bool = False,
@@ -36,8 +35,7 @@ def run(
             cmd,
             cwd=cwd,
             check=True,
-            stdout=subprocess.PIPE,
-            stderr=subprocess.PIPE,
+            capture_output=True,
             text=True,
         )
     except subprocess.CalledProcessError as exc:
diff --git a/src/pkgmgr/core/remote_provisioning/ensure.py b/src/pkgmgr/core/remote_provisioning/ensure.py
index f1335b6..6b03355 100644
--- a/src/pkgmgr/core/remote_provisioning/ensure.py
+++ b/src/pkgmgr/core/remote_provisioning/ensure.py
@@ -2,7 +2,6 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
-from typing import Optional
 
 from pkgmgr.core.credentials.resolver import ResolutionOptions, TokenResolver
 
@@ -45,10 +44,10 @@ def _raise_mapped_http_error(exc: HttpError, host: str) -> None:
 
 def ensure_remote_repo(
     spec: RepoSpec,
-    provider_hint: Optional[ProviderHint] = None,
-    options: Optional[EnsureOptions] = None,
-    registry: Optional[ProviderRegistry] = None,
-    token_resolver: Optional[TokenResolver] = None,
+    provider_hint: ProviderHint | None = None,
+    options: EnsureOptions | None = None,
+    registry: ProviderRegistry | None = None,
+    token_resolver: TokenResolver | None = None,
 ) -> EnsureResult:
     """Ensure that the remote repository exists (create if missing).
 
diff --git a/src/pkgmgr/core/remote_provisioning/http/client.py b/src/pkgmgr/core/remote_provisioning/http/client.py
index 6e34472..42bfe0e 100644
--- a/src/pkgmgr/core/remote_provisioning/http/client.py
+++ b/src/pkgmgr/core/remote_provisioning/http/client.py
@@ -6,7 +6,7 @@ import ssl
 import urllib.error
 import urllib.request
 from dataclasses import dataclass
-from typing import Any, Dict, Optional
+from typing import Any
 
 from .errors import HttpError
 
@@ -15,7 +15,7 @@ from .errors import HttpError
 class HttpResponse:
     status: int
     text: str
-    json: Optional[Dict[str, Any]] = None
+    json: dict[str, Any] | None = None
 
 
 class HttpClient:
@@ -28,11 +28,11 @@ class HttpClient:
         self,
         method: str,
         url: str,
-        headers: Optional[Dict[str, str]] = None,
-        payload: Optional[Dict[str, Any]] = None,
+        headers: dict[str, str] | None = None,
+        payload: dict[str, Any] | None = None,
     ) -> HttpResponse:
-        data: Optional[bytes] = None
-        final_headers: Dict[str, str] = dict(headers or {})
+        data: bytes | None = None
+        final_headers: dict[str, str] = dict(headers or {})
 
         if payload is not None:
             data = json.dumps(payload).encode("utf-8")
diff --git a/src/pkgmgr/core/remote_provisioning/providers/base.py b/src/pkgmgr/core/remote_provisioning/providers/base.py
index 96da7ed..5f479d3 100644
--- a/src/pkgmgr/core/remote_provisioning/providers/base.py
+++ b/src/pkgmgr/core/remote_provisioning/providers/base.py
@@ -49,6 +49,6 @@ class RemoteProvider(ABC):
     @staticmethod
     def _api_base(host: str) -> str:
         # Default to https. If you need http for local dev, store host as "http://..."
-        if host.startswith("http://") or host.startswith("https://"):
+        if host.startswith(("http://", "https://")):
             return host.rstrip("/")
         return f"https://{host}".rstrip("/")
diff --git a/src/pkgmgr/core/remote_provisioning/providers/gitea.py b/src/pkgmgr/core/remote_provisioning/providers/gitea.py
index 1c89b39..4835c68 100644
--- a/src/pkgmgr/core/remote_provisioning/providers/gitea.py
+++ b/src/pkgmgr/core/remote_provisioning/providers/gitea.py
@@ -1,7 +1,7 @@
 # src/pkgmgr/core/remote_provisioning/providers/gitea.py
 from __future__ import annotations
 
-from typing import Any, Dict
+from typing import Any
 
 from ..http.client import HttpClient
 from ..http.errors import HttpError
@@ -25,11 +25,9 @@ class GiteaProvider(RemoteProvider):
         - If you add more providers later, tighten this heuristic or use provider hints.
         """
         h = host.lower()
-        if h in ("github.com", "api.github.com") or h.endswith(".github.com"):
-            return False
-        return True
+        return not (h in ("github.com", "api.github.com") or h.endswith(".github.com"))
 
-    def _headers(self, token: str) -> Dict[str, str]:
+    def _headers(self, token: str) -> dict[str, str]:
         """
         Gitea commonly supports:
           Authorization: token <TOKEN>
@@ -70,7 +68,7 @@ class GiteaProvider(RemoteProvider):
     def set_repo_private(self, token: str, spec: RepoSpec, *, private: bool) -> None:
         base = self._api_base(spec.host)
         url = f"{base}/api/v1/repos/{spec.owner}/{spec.name}"
-        payload: Dict[str, Any] = {"private": bool(private)}
+        payload: dict[str, Any] = {"private": bool(private)}
 
         resp = self._http.request_json(
             "PATCH",
@@ -88,7 +86,7 @@ class GiteaProvider(RemoteProvider):
     def create_repo(self, token: str, spec: RepoSpec) -> EnsureResult:
         base = self._api_base(spec.host)
 
-        payload: Dict[str, Any] = {
+        payload: dict[str, Any] = {
             "name": spec.name,
             "private": bool(spec.private),
         }
diff --git a/src/pkgmgr/core/remote_provisioning/providers/github.py b/src/pkgmgr/core/remote_provisioning/providers/github.py
index 832b39d..7374477 100644
--- a/src/pkgmgr/core/remote_provisioning/providers/github.py
+++ b/src/pkgmgr/core/remote_provisioning/providers/github.py
@@ -1,7 +1,7 @@
 # src/pkgmgr/core/remote_provisioning/providers/github.py
 from __future__ import annotations
 
-from typing import Any, Dict
+from typing import Any
 
 from ..http.client import HttpClient
 from ..http.errors import HttpError
@@ -32,11 +32,11 @@ class GitHubProvider(RemoteProvider):
             return "https://api.github.com"
 
         # Enterprise instance:
-        if host.startswith("http://") or host.startswith("https://"):
+        if host.startswith(("http://", "https://")):
             return host.rstrip("/") + "/api/v3"
         return f"https://{host}/api/v3"
 
-    def _headers(self, token: str) -> Dict[str, str]:
+    def _headers(self, token: str) -> dict[str, str]:
         return {
             "Authorization": f"Bearer {token}",
             "Accept": "application/vnd.github+json",
@@ -72,7 +72,7 @@ class GitHubProvider(RemoteProvider):
     def set_repo_private(self, token: str, spec: RepoSpec, *, private: bool) -> None:
         api = self._api_base(spec.host)
         url = f"{api}/repos/{spec.owner}/{spec.name}"
-        payload: Dict[str, Any] = {"private": bool(private)}
+        payload: dict[str, Any] = {"private": bool(private)}
 
         resp = self._http.request_json(
             "PATCH",
@@ -90,7 +90,7 @@ class GitHubProvider(RemoteProvider):
     def create_repo(self, token: str, spec: RepoSpec) -> EnsureResult:
         api = self._api_base(spec.host)
 
-        payload: Dict[str, Any] = {
+        payload: dict[str, Any] = {
             "name": spec.name,
             "private": bool(spec.private),
         }
diff --git a/src/pkgmgr/core/remote_provisioning/registry.py b/src/pkgmgr/core/remote_provisioning/registry.py
index 04de497..1ffc01b 100644
--- a/src/pkgmgr/core/remote_provisioning/registry.py
+++ b/src/pkgmgr/core/remote_provisioning/registry.py
@@ -2,7 +2,6 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
-from typing import List, Optional
 
 from .providers.base import RemoteProvider
 from .providers.gitea import GiteaProvider
diff --git a/src/pkgmgr/core/remote_provisioning/types.py b/src/pkgmgr/core/remote_provisioning/types.py
index 46b5afd..77befc3 100644
--- a/src/pkgmgr/core/remote_provisioning/types.py
+++ b/src/pkgmgr/core/remote_provisioning/types.py
@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
-from typing import Literal, Optional
+from typing import Literal
 
 EnsureStatus = Literal[
     "exists",
@@ -18,7 +18,7 @@ EnsureStatus = Literal[
 class ProviderHint:
     """Optional hint to force a provider kind."""
 
-    kind: Optional[str] = None  # e.g. "gitea" or "github"
+    kind: str | None = None  # e.g. "gitea" or "github"
 
 
 @dataclass(frozen=True)
@@ -30,14 +30,14 @@ class RepoSpec:
     name: str
     private: bool = True
     description: str = ""
-    default_branch: Optional[str] = None
+    default_branch: str | None = None
 
 
 @dataclass(frozen=True)
 class EnsureResult:
     status: EnsureStatus
     message: str
-    url: Optional[str] = None
+    url: str | None = None
 
 
 class RemoteProvisioningError(RuntimeError):
diff --git a/src/pkgmgr/core/remote_provisioning/visibility.py b/src/pkgmgr/core/remote_provisioning/visibility.py
index 3dc60b1..37c7b21 100644
--- a/src/pkgmgr/core/remote_provisioning/visibility.py
+++ b/src/pkgmgr/core/remote_provisioning/visibility.py
@@ -2,7 +2,6 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
-from typing import Optional
 
 from pkgmgr.core.credentials.resolver import ResolutionOptions, TokenResolver
 
@@ -47,10 +46,10 @@ def set_repo_visibility(
     spec: RepoSpec,
     *,
     private: bool,
-    provider_hint: Optional[ProviderHint] = None,
-    options: Optional[VisibilityOptions] = None,
-    registry: Optional[ProviderRegistry] = None,
-    token_resolver: Optional[TokenResolver] = None,
+    provider_hint: ProviderHint | None = None,
+    options: VisibilityOptions | None = None,
+    registry: ProviderRegistry | None = None,
+    token_resolver: TokenResolver | None = None,
 ) -> EnsureResult:
     """
     Set repository visibility (public/private) WITHOUT creating repositories.
diff --git a/src/pkgmgr/core/repository/dir.py b/src/pkgmgr/core/repository/dir.py
index 3fc84fe..35aa1bf 100644
--- a/src/pkgmgr/core/repository/dir.py
+++ b/src/pkgmgr/core/repository/dir.py
@@ -1,9 +1,9 @@
 import os
 import sys
-from typing import Any, Dict
+from typing import Any
 
 
-def get_repo_dir(repositories_base_dir: str, repo: Dict[str, Any]) -> str:
+def get_repo_dir(repositories_base_dir: str, repo: dict[str, Any]) -> str:
     """
     Build the local repository directory path from:
       repositories_base_dir/provider/account/repository
diff --git a/src/pkgmgr/core/repository/paths.py b/src/pkgmgr/core/repository/paths.py
index b7f1a79..64967fe 100644
--- a/src/pkgmgr/core/repository/paths.py
+++ b/src/pkgmgr/core/repository/paths.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 Central repository path resolver.
 
@@ -20,7 +18,6 @@ from __future__ import annotations
 import os
 from collections.abc import Iterable
 from dataclasses import dataclass
-from typing import Optional
 
 
 @dataclass(frozen=True)
@@ -31,23 +28,23 @@ class RepoPaths:
     flake_nix: str
 
     # Human changelog (typically Markdown)
-    changelog_md: Optional[str]
+    changelog_md: str | None
 
     # Packaging-related files
-    arch_pkgbuild: Optional[str]
-    debian_changelog: Optional[str]
-    debian_control: Optional[str]
-    rpm_spec: Optional[str]
+    arch_pkgbuild: str | None
+    debian_changelog: str | None
+    debian_control: str | None
+    rpm_spec: str | None
 
 
-def _first_existing(candidates: Iterable[str]) -> Optional[str]:
+def _first_existing(candidates: Iterable[str]) -> str | None:
     for p in candidates:
         if p and os.path.isfile(p):
             return p
     return None
 
 
-def _find_first_spec_in_dir(dir_path: str) -> Optional[str]:
+def _find_first_spec_in_dir(dir_path: str) -> str | None:
     if not os.path.isdir(dir_path):
         return None
     try:
diff --git a/src/pkgmgr/core/repository/resolve.py b/src/pkgmgr/core/repository/resolve.py
index 3689e28..ad2a9e9 100644
--- a/src/pkgmgr/core/repository/resolve.py
+++ b/src/pkgmgr/core/repository/resolve.py
@@ -13,12 +13,12 @@ def resolve_repos(identifiers: [], all_repos: []):
             full_id = (
                 f"{repo.get('provider')}/{repo.get('account')}/{repo.get('repository')}"
             )
-            if ident == full_id or ident == repo.get("alias"):
-                matches.append(repo)
-            elif ident == repo.get("repository"):
+            if ident == full_id or ident == repo.get("alias") or (
+                ident == repo.get("repository")
                 # Only match if repository name is unique among all_repos.
-                if sum(1 for r in all_repos if r.get("repository") == ident) == 1:
-                    matches.append(repo)
+                and sum(1 for r in all_repos if r.get("repository") == ident) == 1
+            ):
+                matches.append(repo)
         if not matches:
             print(f"Identifier '{ident}' did not match any repository in config.")
         else:
diff --git a/src/pkgmgr/core/repository/selected.py b/src/pkgmgr/core/repository/selected.py
index 71c317d..704d294 100644
--- a/src/pkgmgr/core/repository/selected.py
+++ b/src/pkgmgr/core/repository/selected.py
@@ -1,16 +1,14 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 import os
 import re
 from collections.abc import Sequence
-from typing import Any, Dict, List
+from typing import Any
 
 from pkgmgr.core.repository.ignored import filter_ignored
 from pkgmgr.core.repository.resolve import resolve_repos
 
-Repository = Dict[str, Any]
+Repository = dict[str, Any]
 
 
 def _compile_maybe_regex(pattern: str):
@@ -42,10 +40,7 @@ def _match_any(values: Sequence[str], pattern: str) -> bool:
     """
     Return True if any of the values matches the pattern.
     """
-    for v in values:
-        if _match_pattern(v, pattern):
-            return True
-    return False
+    return any(_match_pattern(v, pattern) for v in values)
 
 
 def _build_identifier_string(repo: Repository) -> str:
@@ -72,15 +67,15 @@ def _build_identifier_string(repo: Repository) -> str:
 
 
 def _apply_filters(
-    repos: List[Repository],
+    repos: list[Repository],
     string_pattern: str,
-    category_patterns: List[str],
-    tag_patterns: List[str],
-) -> List[Repository]:
+    category_patterns: list[str],
+    tag_patterns: list[str],
+) -> list[Repository]:
     if not string_pattern and not category_patterns and not tag_patterns:
         return repos
 
-    filtered: List[Repository] = []
+    filtered: list[Repository] = []
 
     for repo in repos:
         # String filter
@@ -91,7 +86,7 @@ def _apply_filters(
 
         # Category filter: only real categories, NOT tags
         if category_patterns:
-            cats: List[str] = []
+            cats: list[str] = []
             cats.extend(map(str, repo.get("category_files", [])))
             if "category" in repo:
                 cats.append(str(repo["category"]))
@@ -109,7 +104,7 @@ def _apply_filters(
 
         # Tag filter: YAML tags only
         if tag_patterns:
-            tags: List[str] = list(map(str, repo.get("tags", [])))
+            tags: list[str] = list(map(str, repo.get("tags", [])))
             if not tags:
                 continue
 
@@ -126,7 +121,7 @@ def _apply_filters(
     return filtered
 
 
-def _maybe_filter_ignored(args, repos: List[Repository]) -> List[Repository]:
+def _maybe_filter_ignored(args, repos: list[Repository]) -> list[Repository]:
     """
     Apply ignore filtering unless the caller explicitly opted to include ignored
     repositories (via args.include_ignored).
@@ -141,7 +136,7 @@ def _maybe_filter_ignored(args, repos: List[Repository]) -> List[Repository]:
     return filter_ignored(repos)
 
 
-def get_selected_repos(args, all_repositories: List[Repository]) -> List[Repository]:
+def get_selected_repos(args, all_repositories: list[Repository]) -> list[Repository]:
     """
     Compute the list of repositories selected by CLI arguments.
 
@@ -158,11 +153,11 @@ def get_selected_repos(args, all_repositories: List[Repository]) -> List[Reposit
     The ignore filter can be bypassed by setting args.include_ignored = True
     (e.g. via a CLI flag --include-ignored).
     """
-    identifiers: List[str] = getattr(args, "identifiers", []) or []
+    identifiers: list[str] = getattr(args, "identifiers", []) or []
     use_all: bool = bool(getattr(args, "all", False))
-    category_patterns: List[str] = getattr(args, "category", []) or []
+    category_patterns: list[str] = getattr(args, "category", []) or []
     string_pattern: str = getattr(args, "string", "") or ""
-    tag_patterns: List[str] = getattr(args, "tag", []) or []
+    tag_patterns: list[str] = getattr(args, "tag", []) or []
 
     has_filters = bool(category_patterns or string_pattern or tag_patterns)
 
diff --git a/src/pkgmgr/core/version/installed.py b/src/pkgmgr/core/version/installed.py
index 3bd3287..6ef9b60 100644
--- a/src/pkgmgr/core/version/installed.py
+++ b/src/pkgmgr/core/version/installed.py
@@ -6,7 +6,6 @@ import shutil
 import subprocess
 from collections.abc import Iterable
 from dataclasses import dataclass
-from typing import Optional, Tuple
 
 
 @dataclass(frozen=True)
@@ -37,7 +36,7 @@ def _unique_candidates(names: Iterable[str]) -> list[str]:
     return out
 
 
-def get_installed_python_version(*candidates: str) -> Optional[InstalledVersion]:
+def get_installed_python_version(*candidates: str) -> InstalledVersion | None:
     """
     Detect installed Python package version in the CURRENT Python environment.
 
@@ -86,18 +85,17 @@ def get_installed_python_version(*candidates: str) -> Optional[InstalledVersion]
     return None
 
 
-def _run_nix(args: list[str]) -> Tuple[int, str, str]:
+def _run_nix(args: list[str]) -> tuple[int, str, str]:
     p = subprocess.run(
         args,
-        stdout=subprocess.PIPE,
-        stderr=subprocess.PIPE,
+        capture_output=True,
         text=True,
         check=False,
     )
     return p.returncode, p.stdout or "", p.stderr or ""
 
 
-def _extract_version_from_store_path(path: str) -> Optional[str]:
+def _extract_version_from_store_path(path: str) -> str | None:
     if not path:
         return None
     base = path.rstrip("/").split("/")[-1]
@@ -109,7 +107,7 @@ def _extract_version_from_store_path(path: str) -> Optional[str]:
     return None
 
 
-def get_installed_nix_profile_version(*candidates: str) -> Optional[InstalledVersion]:
+def get_installed_nix_profile_version(*candidates: str) -> InstalledVersion | None:
     """
     Detect installed version from the current Nix profile.
 
diff --git a/src/pkgmgr/core/version/semver.py b/src/pkgmgr/core/version/semver.py
index 77e4a39..4845ed7 100644
--- a/src/pkgmgr/core/version/semver.py
+++ b/src/pkgmgr/core/version/semver.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 Utilities for working with semantic versions (SemVer).
 
@@ -12,7 +10,6 @@ from __future__ import annotations
 
 from collections.abc import Iterable
 from dataclasses import dataclass
-from typing import List, Optional, Tuple
 
 
 @dataclass(frozen=True, order=True)
@@ -79,16 +76,16 @@ def is_semver_tag(tag: str) -> bool:
 
 def extract_semver_from_tags(
     tags: Iterable[str],
-    major: Optional[int] = None,
-    minor: Optional[int] = None,
-) -> List[Tuple[str, SemVer]]:
+    major: int | None = None,
+    minor: int | None = None,
+) -> list[tuple[str, SemVer]]:
     """
     Filter and parse tags that match SemVer, optionally restricted
     to a specific MAJOR or MAJOR.MINOR line.
 
     Returns a list of (tag_string, SemVer) pairs.
     """
-    result: List[Tuple[str, SemVer]] = []
+    result: list[tuple[str, SemVer]] = []
     for tag in tags:
         try:
             ver = SemVer.parse(tag)
@@ -108,9 +105,9 @@ def extract_semver_from_tags(
 
 def find_latest_version(
     tags: Iterable[str],
-    major: Optional[int] = None,
-    minor: Optional[int] = None,
-) -> Optional[Tuple[str, SemVer]]:
+    major: int | None = None,
+    minor: int | None = None,
+) -> tuple[str, SemVer] | None:
     """
     Find the latest SemVer tag from the given tags.
 
diff --git a/src/pkgmgr/core/version/source.py b/src/pkgmgr/core/version/source.py
index 2ded27b..e250905 100644
--- a/src/pkgmgr/core/version/source.py
+++ b/src/pkgmgr/core/version/source.py
@@ -3,14 +3,13 @@ from __future__ import annotations
 
 import os
 import re
-from typing import Optional
 
 import yaml
 
 from pkgmgr.core.repository.paths import resolve_repo_paths
 
 
-def read_pyproject_version(repo_dir: str) -> Optional[str]:
+def read_pyproject_version(repo_dir: str) -> str | None:
     """
     Read the version from pyproject.toml in repo_dir, if present.
 
@@ -88,7 +87,7 @@ def read_flake_version(repo_dir: str) -> Optional[str]:
     return match.group(1).strip() or None
 
 
-def read_pkgbuild_version(repo_dir: str) -> Optional[str]:
+def read_pkgbuild_version(repo_dir: str) -> str | None:
     """
     Read the version from PKGBUILD (preferring packaging/arch/PKGBUILD).
 
@@ -122,7 +121,7 @@ def read_pkgbuild_version(repo_dir: str) -> Optional[str]:
     return pkgver or None
 
 
-def read_debian_changelog_version(repo_dir: str) -> Optional[str]:
+def read_debian_changelog_version(repo_dir: str) -> str | None:
     """
     Read the latest version from debian changelog.
 
@@ -140,7 +139,7 @@ def read_debian_changelog_version(repo_dir: str) -> Optional[str]:
         return None
 
     try:
-        with open(path, "r", encoding="utf-8") as f:
+        with open(path, encoding="utf-8") as f:
             for line in f:
                 line = line.strip()
                 if not line:
@@ -195,7 +194,7 @@ def read_spec_version(repo_dir: str) -> Optional[str]:
     return version or None
 
 
-def read_ansible_galaxy_version(repo_dir: str) -> Optional[str]:
+def read_ansible_galaxy_version(repo_dir: str) -> str | None:
     """
     Read the version from Ansible Galaxy metadata.
 
diff --git a/src/pkgmgr/github/check_hadolint_sarif.py b/src/pkgmgr/github/check_hadolint_sarif.py
index 45053ce..f8f5830 100644
--- a/src/pkgmgr/github/check_hadolint_sarif.py
+++ b/src/pkgmgr/github/check_hadolint_sarif.py
@@ -1,4 +1,3 @@
-#!/usr/bin/env python3
 """Fail when a hadolint SARIF report contains warnings or errors."""
 
 from __future__ import annotations
diff --git a/tests/e2e/_util.py b/tests/e2e/_util.py
index fbf313c..42a3083 100644
--- a/tests/e2e/_util.py
+++ b/tests/e2e/_util.py
@@ -10,6 +10,7 @@ def run(cmd, *, cwd=None, env=None, shell=False) -> str:
         text=True,
         stdout=subprocess.PIPE,
         stderr=subprocess.STDOUT,
+        check=False,
     )
 
     print("----- BEGIN COMMAND -----")
diff --git a/tests/e2e/test_config_commands.py b/tests/e2e/test_config_commands.py
index ea1ab5e..1fe2a6e 100644
--- a/tests/e2e/test_config_commands.py
+++ b/tests/e2e/test_config_commands.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 Integration tests for the `pkgmgr config` command.
 
diff --git a/tests/e2e/test_make_commands.py b/tests/e2e/test_make_commands.py
index 4a4cf78..42da6b5 100644
--- a/tests/e2e/test_make_commands.py
+++ b/tests/e2e/test_make_commands.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 Integration tests for the `pkgmgr make` command.
 
diff --git a/tests/e2e/test_nix_build_pkgmgr.py b/tests/e2e/test_nix_build_pkgmgr.py
index 92f3b29..7dfa33e 100644
--- a/tests/e2e/test_nix_build_pkgmgr.py
+++ b/tests/e2e/test_nix_build_pkgmgr.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 E2E test to inspect the Nix environment and build the pkgmgr flake
 in *every* distro container.
@@ -36,6 +34,7 @@ def _run_cmd(cmd: list[str]) -> subprocess.CompletedProcess:
         cmd,
         text=True,
         capture_output=True,
+        check=False,
     )
     print("[STDOUT]\n", proc.stdout)
     print("[STDERR]\n", proc.stderr)
diff --git a/tests/e2e/test_path_commands.py b/tests/e2e/test_path_commands.py
index a8f5eed..e61f942 100644
--- a/tests/e2e/test_path_commands.py
+++ b/tests/e2e/test_path_commands.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 End-to-end tests for the `pkgmgr path` command.
 
diff --git a/tests/e2e/test_release_commands.py b/tests/e2e/test_release_commands.py
index 5869313..a8f4fa7 100644
--- a/tests/e2e/test_release_commands.py
+++ b/tests/e2e/test_release_commands.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 End-to-end style integration tests for the `pkgmgr release` CLI command.
 
@@ -149,9 +147,12 @@ class TestIntegrationReleaseCommand(unittest.TestCase):
         try:
             sys.argv = ["pkgmgr", "release", "--help"]
             # argparse will call sys.exit(), so we expect a SystemExit here.
-            with contextlib.redirect_stdout(buf), contextlib.redirect_stderr(buf):
-                with self.assertRaises(SystemExit) as cm:
-                    runpy.run_module("pkgmgr", run_name="__main__")
+            with (
+                contextlib.redirect_stdout(buf),
+                contextlib.redirect_stderr(buf),
+                self.assertRaises(SystemExit) as cm,
+            ):
+                runpy.run_module("pkgmgr", run_name="__main__")
         finally:
             sys.argv = original_argv
 
diff --git a/tests/e2e/test_tools_commands.py b/tests/e2e/test_tools_commands.py
index 0886e0a..471b47c 100644
--- a/tests/e2e/test_tools_commands.py
+++ b/tests/e2e/test_tools_commands.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 Integration tests for the "tools" commands:
 
diff --git a/tests/e2e/test_tools_help.py b/tests/e2e/test_tools_help.py
index 68cb440..02a3487 100644
--- a/tests/e2e/test_tools_help.py
+++ b/tests/e2e/test_tools_help.py
@@ -15,10 +15,9 @@ from __future__ import annotations
 import runpy
 import sys
 import unittest
-from typing import List
 
 
-def _run_main(argv: List[str]) -> None:
+def _run_main(argv: list[str]) -> None:
     """
     Helper to run main.py with the given argv.
 
diff --git a/tests/e2e/test_version_commands.py b/tests/e2e/test_version_commands.py
index 31fe14b..7e526d0 100644
--- a/tests/e2e/test_version_commands.py
+++ b/tests/e2e/test_version_commands.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 End-to-end tests for the `pkgmgr version` command.
 
@@ -25,7 +23,6 @@ import os
 import runpy
 import sys
 import unittest
-from typing import List
 
 from pkgmgr.core.config.load import load_config
 
@@ -54,7 +51,7 @@ def _load_pkgmgr_repo_dir() -> str:
     directories = cfg.get("directories", {})
     base_repos_dir = os.path.expanduser(directories.get("repositories", ""))
 
-    candidates: List[dict] = cfg.get("repositories", []) or []
+    candidates: list[dict] = cfg.get("repositories", []) or []
     for repo in candidates:
         repo_name = (repo.get("repository") or "").strip()
         alias = (repo.get("alias") or "").strip()
diff --git a/tests/integration/test_branch_cli.py b/tests/integration/test_branch_cli.py
index 95bd2fc..63d93d0 100644
--- a/tests/integration/test_branch_cli.py
+++ b/tests/integration/test_branch_cli.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 Integration tests for the `pkgmgr branch` CLI wiring.
 
diff --git a/tests/integration/test_config_defaults_integration.py b/tests/integration/test_config_defaults_integration.py
index 33a61e0..581fe4b 100644
--- a/tests/integration/test_config_defaults_integration.py
+++ b/tests/integration/test_config_defaults_integration.py
@@ -67,51 +67,53 @@ class ConfigDefaultsIntegrationTest(unittest.TestCase):
             # Provide fake pkgmgr module so your functions resolve pkg_root correctly
             fake_pkgmgr = types.SimpleNamespace(__file__=str(pkg_root / "__init__.py"))
 
-            with patch.dict(sys.modules, {"pkgmgr": fake_pkgmgr}):
-                with patch.dict(os.environ, {"HOME": str(home)}):
-                    # A) load_config should fall back to <pkg_root>/config/defaults.yaml
-                    merged = load_config(user_config_path)
+            with (
+                patch.dict(sys.modules, {"pkgmgr": fake_pkgmgr}),
+                patch.dict(os.environ, {"HOME": str(home)}),
+            ):
+                # A) load_config should fall back to <pkg_root>/config/defaults.yaml
+                merged = load_config(user_config_path)
 
-                    self.assertEqual(
-                        merged["directories"]["repositories"], "/opt/Repositories"
-                    )
-                    self.assertEqual(
-                        merged["directories"]["binaries"], "/usr/local/bin"
-                    )
+                self.assertEqual(
+                    merged["directories"]["repositories"], "/opt/Repositories"
+                )
+                self.assertEqual(
+                    merged["directories"]["binaries"], "/usr/local/bin"
+                )
 
-                    # user-only key must still exist (user config merges over defaults)
-                    self.assertEqual(merged["directories"]["user_only"], "/home/user")
+                # user-only key must still exist (user config merges over defaults)
+                self.assertEqual(merged["directories"]["user_only"], "/home/user")
 
-                    self.assertIn("repositories", merged)
-                    self.assertTrue(
-                        any(
-                            r.get("provider") == "github"
-                            and r.get("account") == "acme"
-                            and r.get("repository") == "demo"
-                            for r in merged["repositories"]
-                        )
+                self.assertIn("repositories", merged)
+                self.assertTrue(
+                    any(
+                        r.get("provider") == "github"
+                        and r.get("account") == "acme"
+                        and r.get("repository") == "demo"
+                        for r in merged["repositories"]
                     )
+                )
 
-                    # B) update_default_configs should copy defaults.yaml to ~/.config/pkgmgr/
-                    before_config_yaml = (user_cfg_dir / "config.yaml").read_text(
-                        encoding="utf-8"
-                    )
+                # B) update_default_configs should copy defaults.yaml to ~/.config/pkgmgr/
+                before_config_yaml = (user_cfg_dir / "config.yaml").read_text(
+                    encoding="utf-8"
+                )
 
-                    config_cmd._update_default_configs(user_config_path)
+                config_cmd._update_default_configs(user_config_path)
 
-                    self.assertTrue((user_cfg_dir / "defaults.yaml").is_file())
-                    copied_defaults = yaml.safe_load(
-                        (user_cfg_dir / "defaults.yaml").read_text(encoding="utf-8")
-                    )
-                    self.assertEqual(
-                        copied_defaults["directories"]["repositories"],
-                        "/opt/Repositories",
-                    )
+                self.assertTrue((user_cfg_dir / "defaults.yaml").is_file())
+                copied_defaults = yaml.safe_load(
+                    (user_cfg_dir / "defaults.yaml").read_text(encoding="utf-8")
+                )
+                self.assertEqual(
+                    copied_defaults["directories"]["repositories"],
+                    "/opt/Repositories",
+                )
 
-                    after_config_yaml = (user_cfg_dir / "config.yaml").read_text(
-                        encoding="utf-8"
-                    )
-                    self.assertEqual(after_config_yaml, before_config_yaml)
+                after_config_yaml = (user_cfg_dir / "config.yaml").read_text(
+                    encoding="utf-8"
+                )
+                self.assertEqual(after_config_yaml, before_config_yaml)
 
 
 if __name__ == "__main__":
diff --git a/tests/integration/test_install_repos.py b/tests/integration/test_install_repos.py
index 1fe61c1..ecac640 100644
--- a/tests/integration/test_install_repos.py
+++ b/tests/integration/test_install_repos.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 import os
 import tempfile
 import unittest
@@ -134,9 +132,7 @@ class TestInstallReposIntegration(unittest.TestCase):
                     Make _ensure_repo_dir() believe that the repo directories
                     already exist so that it does not attempt cloning.
                     """
-                    if path in (repo_system_dir, repo_nix_dir):
-                        return True
-                    return False
+                    return path in (repo_system_dir, repo_nix_dir)
 
                 mock_resolve.side_effect = fake_resolve
                 mock_exists_install.side_effect = fake_exists_install
diff --git a/tests/integration/test_mirror_commands.py b/tests/integration/test_mirror_commands.py
index ff26d5f..69efd61 100644
--- a/tests/integration/test_mirror_commands.py
+++ b/tests/integration/test_mirror_commands.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 CLI integration tests for `pkgmgr mirror`.
 
@@ -21,7 +19,6 @@ import runpy
 import sys
 import unittest
 from contextlib import ExitStack, redirect_stderr, redirect_stdout
-from typing import Dict, List, Optional
 from unittest.mock import MagicMock, PropertyMock, patch
 
 
@@ -29,7 +26,7 @@ class TestIntegrationMirrorCommands(unittest.TestCase):
     """Integration tests for `pkgmgr mirror` commands."""
 
     def _run_pkgmgr(
-        self, args: List[str], extra_env: Optional[Dict[str, str]] = None
+        self, args: list[str], extra_env: dict[str, str] | None = None
     ) -> str:
         """Execute pkgmgr with the given arguments and return captured output."""
         original_argv = list(sys.argv)
@@ -151,8 +148,7 @@ class TestIntegrationMirrorCommands(unittest.TestCase):
                         code = exc.code if isinstance(exc.code, int) else None
                         if code not in (0, None):
                             raise AssertionError(
-                                "%r failed with exit code %r.\n\nOutput:\n%s"
-                                % (cmd_repr, exc.code, buffer.getvalue())
+                                f"{cmd_repr!r} failed with exit code {exc.code!r}.\n\nOutput:\n{buffer.getvalue()}"
                             )
 
             return buffer.getvalue()
diff --git a/tests/integration/test_mirror_probe_detail_and_provision.py b/tests/integration/test_mirror_probe_detail_and_provision.py
index 75dc39f..137a68d 100644
--- a/tests/integration/test_mirror_probe_detail_and_provision.py
+++ b/tests/integration/test_mirror_probe_detail_and_provision.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 Integration test for mirror probing + provisioning after refactor.
 
diff --git a/tests/integration/test_recursive_capabilities.py b/tests/integration/test_recursive_capabilities.py
index 8927c57..45f8bbb 100644
--- a/tests/integration/test_recursive_capabilities.py
+++ b/tests/integration/test_recursive_capabilities.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 Integration tests for recursive capability resolution and installer shadowing.
 
@@ -17,7 +15,6 @@ import shutil
 import tempfile
 import unittest
 from collections.abc import Sequence
-from typing import List, Tuple
 from unittest.mock import patch
 
 import pkgmgr.actions.install as install_mod
@@ -29,7 +26,7 @@ from pkgmgr.actions.install.installers.os_packages.arch_pkgbuild import (
 )
 from pkgmgr.actions.install.installers.python import PythonInstaller
 
-InstallerSpec = Tuple[str, object]
+InstallerSpec = tuple[str, object]
 
 
 class TestRecursiveCapabilitiesIntegration(unittest.TestCase):
@@ -54,7 +51,7 @@ class TestRecursiveCapabilitiesIntegration(unittest.TestCase):
         repo_dir: str,
         installers: Sequence[InstallerSpec],
         selected_repos=None,
-    ) -> List[str]:
+    ) -> list[str]:
         """
         Run install_repos() with a custom INSTALLERS list and capture which
         installer labels actually run.
@@ -69,7 +66,7 @@ class TestRecursiveCapabilitiesIntegration(unittest.TestCase):
         else:
             all_repos = selected_repos
 
-        called_installers: List[str] = []
+        called_installers: list[str] = []
 
         patched_installers = []
         for label, inst in installers:
diff --git a/tests/integration/test_token_resolver_flow.py b/tests/integration/test_token_resolver_flow.py
index 0e5afe9..82b6f29 100644
--- a/tests/integration/test_token_resolver_flow.py
+++ b/tests/integration/test_token_resolver_flow.py
@@ -21,62 +21,46 @@ class TestTokenResolverIntegration(unittest.TestCase):
 
         resolver = TokenResolver()
 
-        # ------------------------------------------------------------------
-        # 1) ENV: empty
-        # ------------------------------------------------------------------
-        with patch.dict("os.environ", {}, clear=True):
-            # ------------------------------------------------------------------
-            # 2) GH CLI is available
-            # ------------------------------------------------------------------
-            with patch(
+        def validate_side_effect(
+            provider_kind: str,
+            host: str,
+            token: str,
+        ) -> bool:
+            return False  # gh + keyring invalid
+
+        with (
+            patch.dict("os.environ", {}, clear=True),
+            patch(
                 "pkgmgr.core.credentials.providers.gh.shutil.which",
                 return_value="/usr/bin/gh",
-            ):
-                with patch(
-                    "pkgmgr.core.credentials.providers.gh.subprocess.check_output",
-                    return_value="gh-invalid-token\n",
-                ):
-                    # ------------------------------------------------------------------
-                    # 3) Keyring returns an existing (invalid) token
-                    # ------------------------------------------------------------------
-                    with patch(
-                        "pkgmgr.core.credentials.providers.keyring._import_keyring"
-                    ) as mock_import_keyring:
-                        mock_keyring = mock_import_keyring.return_value
-                        mock_keyring.get_password.return_value = "keyring-invalid-token"
+            ),
+            patch(
+                "pkgmgr.core.credentials.providers.gh.subprocess.check_output",
+                return_value="gh-invalid-token\n",
+            ),
+            patch(
+                "pkgmgr.core.credentials.providers.keyring._import_keyring"
+            ) as mock_import_keyring,
+            patch(
+                "pkgmgr.core.credentials.providers.prompt.sys.stdin.isatty",
+                return_value=True,
+            ),
+            patch(
+                "pkgmgr.core.credentials.providers.prompt.getpass",
+                return_value="new-valid-token",
+            ),
+            patch(
+                "pkgmgr.core.credentials.resolver.validate_token",
+                side_effect=validate_side_effect,
+            ) as validate_mock,
+        ):
+            mock_keyring = mock_import_keyring.return_value
+            mock_keyring.get_password.return_value = "keyring-invalid-token"
 
-                        # ------------------------------------------------------------------
-                        # 4) Prompt is allowed and returns a NEW token
-                        # ------------------------------------------------------------------
-                        with patch(
-                            "pkgmgr.core.credentials.providers.prompt.sys.stdin.isatty",
-                            return_value=True,
-                        ):
-                            with patch(
-                                "pkgmgr.core.credentials.providers.prompt.getpass",
-                                return_value="new-valid-token",
-                            ):
-                                # ------------------------------------------------------------------
-                                # 5) Validation logic:
-                                #    - gh token invalid
-                                #    - keyring token invalid
-                                #    - prompt token is NOT validated (by design)
-                                # ------------------------------------------------------------------
-                                def validate_side_effect(
-                                    provider_kind: str,
-                                    host: str,
-                                    token: str,
-                                ) -> bool:
-                                    return False  # gh + keyring invalid
-
-                                with patch(
-                                    "pkgmgr.core.credentials.resolver.validate_token",
-                                    side_effect=validate_side_effect,
-                                ) as validate_mock:
-                                    result = resolver.get_token(
-                                        provider_kind="github",
-                                        host="github.com",
-                                    )
+            result = resolver.get_token(
+                provider_kind="github",
+                host="github.com",
+            )
 
         # ----------------------------------------------------------------------
         # Assertions
@@ -93,7 +77,7 @@ class TestTokenResolverIntegration(unittest.TestCase):
 
         # Keyring must be overwritten with the new token
         mock_keyring.set_password.assert_called_once()
-        service, username, stored_token = mock_keyring.set_password.call_args.args
+        _service, _username, stored_token = mock_keyring.set_password.call_args.args
         self.assertEqual(stored_token, "new-valid-token")
 
 
diff --git a/tests/integration/test_update_silent_continues.py b/tests/integration/test_update_silent_continues.py
index 8d8af1b..f42e84b 100644
--- a/tests/integration/test_update_silent_continues.py
+++ b/tests/integration/test_update_silent_continues.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 import unittest
diff --git a/tests/integration/test_visibility_integration.py b/tests/integration/test_visibility_integration.py
index 4156069..5cc38c8 100644
--- a/tests/integration/test_visibility_integration.py
+++ b/tests/integration/test_visibility_integration.py
@@ -7,14 +7,14 @@ import tempfile
 import types
 import unittest
 from contextlib import redirect_stdout
-from typing import Any, Dict, List, Optional, Tuple
+from typing import Any
 from unittest.mock import patch
 
 from pkgmgr.actions.mirror.setup_cmd import setup_mirrors
 from pkgmgr.actions.mirror.visibility_cmd import set_mirror_visibility
 from pkgmgr.core.remote_provisioning.types import RepoSpec
 
-Repository = Dict[str, Any]
+Repository = dict[str, Any]
 
 
 class _FakeRegistry:
@@ -45,13 +45,13 @@ class FakeProvider:
 
     def __init__(self) -> None:
         # maps (host, owner, name) -> private(bool)
-        self.privacy: Dict[Tuple[str, str, str], bool] = {}
-        self.calls: List[Tuple[str, Any]] = []
+        self.privacy: dict[tuple[str, str, str], bool] = {}
+        self.calls: list[tuple[str, Any]] = []
 
     def can_handle(self, host: str) -> bool:
         return True
 
-    def _candidate_hosts(self, host: str) -> List[str]:
+    def _candidate_hosts(self, host: str) -> list[str]:
         """
         Be tolerant against host normalization differences:
         - may contain scheme (https://...)
@@ -75,7 +75,7 @@ class FakeProvider:
                 candidates.append(c.split(":", 1)[0])
 
         # de-dup
-        out: List[str] = []
+        out: list[str] = []
         for c in candidates:
             if c not in out:
                 out.append(c)
@@ -94,7 +94,7 @@ class FakeProvider:
         self.privacy[(spec.host, spec.owner, spec.name)] = bool(spec.private)
         return types.SimpleNamespace(status="created", message="created", url=None)
 
-    def get_repo_private(self, token: str, spec: RepoSpec) -> Optional[bool]:
+    def get_repo_private(self, token: str, spec: RepoSpec) -> bool | None:
         self.calls.append(("get_repo_private", (token, spec)))
         for h in self._candidate_hosts(spec.host):
             key = (h, spec.owner, spec.name)
@@ -113,7 +113,7 @@ class FakeProvider:
         self.privacy[(spec.host, spec.owner, spec.name)] = bool(private)
 
 
-def _mk_ctx(*, identifier: str, repo_dir: str, mirrors: Dict[str, str]) -> Any:
+def _mk_ctx(*, identifier: str, repo_dir: str, mirrors: dict[str, str]) -> Any:
     return types.SimpleNamespace(
         identifier=identifier,
         repo_dir=repo_dir,
diff --git a/tests/unit/pkgmgr/actions/branch/test_open_branch.py b/tests/unit/pkgmgr/actions/branch/test_open_branch.py
index 502692b..0131e63 100644
--- a/tests/unit/pkgmgr/actions/branch/test_open_branch.py
+++ b/tests/unit/pkgmgr/actions/branch/test_open_branch.py
@@ -54,9 +54,11 @@ class TestOpenBranch(unittest.TestCase):
         push_upstream.assert_called_once_with("origin", "auto-branch", cwd=".")
 
     def test_open_branch_rejects_empty_name(self) -> None:
-        with patch("builtins.input", return_value=""):
-            with self.assertRaises(RuntimeError):
-                open_branch(None)
+        with (
+            patch("builtins.input", return_value=""),
+            self.assertRaises(RuntimeError),
+        ):
+            open_branch(None)
 
 
 if __name__ == "__main__":
diff --git a/tests/unit/pkgmgr/actions/code_scanning/test_code_scanning.py b/tests/unit/pkgmgr/actions/code_scanning/test_code_scanning.py
index 17a3d76..52781ce 100644
--- a/tests/unit/pkgmgr/actions/code_scanning/test_code_scanning.py
+++ b/tests/unit/pkgmgr/actions/code_scanning/test_code_scanning.py
@@ -87,9 +87,11 @@ class TestDownloadCodeScanning(unittest.TestCase):
         )
 
     def test_errors_when_gh_missing(self) -> None:
-        with mock.patch("pkgmgr.actions.code_scanning.shutil.which", return_value=None):
-            with self.assertRaises(CodeScanningError):
-                download_code_scanning(output_dir="/tmp/should-not-be-created")
+        with (
+            mock.patch("pkgmgr.actions.code_scanning.shutil.which", return_value=None),
+            self.assertRaises(CodeScanningError),
+        ):
+            download_code_scanning(output_dir="/tmp/should-not-be-created")
 
 
 if __name__ == "__main__":  # pragma: no cover
diff --git a/tests/unit/pkgmgr/actions/install/installers/nix/_fakes.py b/tests/unit/pkgmgr/actions/install/installers/nix/_fakes.py
index 025ca01..9684f8f 100644
--- a/tests/unit/pkgmgr/actions/install/installers/nix/_fakes.py
+++ b/tests/unit/pkgmgr/actions/install/installers/nix/_fakes.py
@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
-from typing import Any, Optional
+from typing import Any
 
 
 @dataclass
@@ -18,7 +18,7 @@ class FakeRunner:
       - Generic runner.run(ctx, cmd, allow_failure=...)
     """
 
-    def __init__(self, mapping: Optional[dict[str, Any]] = None, default: Any = None):
+    def __init__(self, mapping: dict[str, Any] | None = None, default: Any = None):
         self.mapping = mapping or {}
         self.default = default if default is not None else FakeRunResult(0, "", "")
         self.calls: list[tuple[Any, str, bool]] = []
diff --git a/tests/unit/pkgmgr/actions/install/installers/nix/test_legacy.py b/tests/unit/pkgmgr/actions/install/installers/nix/test_legacy.py
index 9595cda..d9048bb 100644
--- a/tests/unit/pkgmgr/actions/install/installers/nix/test_legacy.py
+++ b/tests/unit/pkgmgr/actions/install/installers/nix/test_legacy.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 Unit tests for NixFlakeInstaller using unittest (no pytest).
 
@@ -19,7 +17,6 @@ import subprocess
 import tempfile
 import unittest
 from contextlib import redirect_stdout
-from typing import List
 from unittest.mock import patch
 
 from pkgmgr.actions.install.installers.nix import NixFlakeInstaller
@@ -73,8 +70,8 @@ class TestNixFlakeInstaller(unittest.TestCase):
         which_patch.return_value = "/usr/bin/nix"
 
     @staticmethod
-    def _install_cmds_from_calls(call_args_list) -> List[str]:
-        cmds: List[str] = []
+    def _install_cmds_from_calls(call_args_list) -> list[str]:
+        cmds: list[str] = []
         for c in call_args_list:
             if not c.args:
                 continue
diff --git a/tests/unit/pkgmgr/actions/install/installers/test_makefile_installer.py b/tests/unit/pkgmgr/actions/install/installers/test_makefile_installer.py
index a6f96ec..055ed3f 100644
--- a/tests/unit/pkgmgr/actions/install/installers/test_makefile_installer.py
+++ b/tests/unit/pkgmgr/actions/install/installers/test_makefile_installer.py
@@ -50,7 +50,6 @@ class TestMakefileInstaller(unittest.TestCase):
         # Ensure we checked the Makefile and then called make install.
         mock_file.assert_called_once_with(
             os.path.join(self.ctx.repo_dir, "Makefile"),
-            "r",
             encoding="utf-8",
             errors="ignore",
         )
@@ -77,7 +76,6 @@ class TestMakefileInstaller(unittest.TestCase):
         # We should have read the Makefile, but not called run_command().
         mock_file.assert_called_once_with(
             os.path.join(self.ctx.repo_dir, "Makefile"),
-            "r",
             encoding="utf-8",
             errors="ignore",
         )
diff --git a/tests/unit/pkgmgr/actions/install/test_install_repos.py b/tests/unit/pkgmgr/actions/install/test_install_repos.py
index ee785d4..18dfe73 100644
--- a/tests/unit/pkgmgr/actions/install/test_install_repos.py
+++ b/tests/unit/pkgmgr/actions/install/test_install_repos.py
@@ -1,13 +1,11 @@
-#!/usr/bin/env python3
-
 import os
 import unittest
-from typing import Any, Dict, List
+from typing import Any
 from unittest.mock import MagicMock, patch
 
 from pkgmgr.actions.install import install_repos
 
-Repository = Dict[str, Any]
+Repository = dict[str, Any]
 
 
 class TestInstallReposOrchestration(unittest.TestCase):
@@ -27,7 +25,7 @@ class TestInstallReposOrchestration(unittest.TestCase):
             "alias": "repo-two",
             "verified": {"gpg_keys": ["FAKEKEY"]},
         }
-        self.all_repos: List[Repository] = [self.repo1, self.repo2]
+        self.all_repos: list[Repository] = [self.repo1, self.repo2]
 
     @patch("pkgmgr.actions.install.InstallationPipeline")
     @patch("pkgmgr.actions.install.clone_repos")
diff --git a/tests/unit/pkgmgr/actions/install/test_layers.py b/tests/unit/pkgmgr/actions/install/test_layers.py
index b7f58c4..0544b28 100644
--- a/tests/unit/pkgmgr/actions/install/test_layers.py
+++ b/tests/unit/pkgmgr/actions/install/test_layers.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 import os
 import unittest
 
diff --git a/tests/unit/pkgmgr/actions/install/test_pipeline.py b/tests/unit/pkgmgr/actions/install/test_pipeline.py
index c3d34c4..717dc94 100644
--- a/tests/unit/pkgmgr/actions/install/test_pipeline.py
+++ b/tests/unit/pkgmgr/actions/install/test_pipeline.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python3
+from __future__ import annotations
 
 import unittest
 from unittest.mock import MagicMock, patch
diff --git a/tests/unit/pkgmgr/actions/mirror/test_context.py b/tests/unit/pkgmgr/actions/mirror/test_context.py
index 9e0c38e..65871c5 100644
--- a/tests/unit/pkgmgr/actions/mirror/test_context.py
+++ b/tests/unit/pkgmgr/actions/mirror/test_context.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 import unittest
diff --git a/tests/unit/pkgmgr/actions/mirror/test_diff_cmd.py b/tests/unit/pkgmgr/actions/mirror/test_diff_cmd.py
index 2fc28f2..d1a6cea 100644
--- a/tests/unit/pkgmgr/actions/mirror/test_diff_cmd.py
+++ b/tests/unit/pkgmgr/actions/mirror/test_diff_cmd.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 import io
diff --git a/tests/unit/pkgmgr/actions/mirror/test_io.py b/tests/unit/pkgmgr/actions/mirror/test_io.py
index 4fba34f..0377f92 100644
--- a/tests/unit/pkgmgr/actions/mirror/test_io.py
+++ b/tests/unit/pkgmgr/actions/mirror/test_io.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 import os
@@ -61,13 +59,7 @@ class TestMirrorIO(unittest.TestCase):
             p = os.path.join(tmpdir, "MIRRORS")
             with open(p, "w", encoding="utf-8") as fh:
                 fh.write(
-                    "\n".join(
-                        [
-                            "https://github.com/alice/repo1",
-                            "https://github.com/alice/repo2",
-                            "ssh://git@git.veen.world:2201/alice/repo3.git",
-                        ]
-                    )
+                    "https://github.com/alice/repo1\nhttps://github.com/alice/repo2\nssh://git@git.veen.world:2201/alice/repo3.git"
                     + "\n"
                 )
 
@@ -99,7 +91,7 @@ class TestMirrorIO(unittest.TestCase):
             p = os.path.join(tmpdir, "MIRRORS")
             self.assertTrue(os.path.exists(p))
 
-            with open(p, "r", encoding="utf-8") as fh:
+            with open(p, encoding="utf-8") as fh:
                 content = fh.read()
 
         self.assertEqual(
diff --git a/tests/unit/pkgmgr/actions/mirror/test_list_cmd.py b/tests/unit/pkgmgr/actions/mirror/test_list_cmd.py
index f0ac9fd..f4ac558 100644
--- a/tests/unit/pkgmgr/actions/mirror/test_list_cmd.py
+++ b/tests/unit/pkgmgr/actions/mirror/test_list_cmd.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 import io
diff --git a/tests/unit/pkgmgr/actions/mirror/test_remote_provision.py b/tests/unit/pkgmgr/actions/mirror/test_remote_provision.py
index 1ce0567..d8d6772 100644
--- a/tests/unit/pkgmgr/actions/mirror/test_remote_provision.py
+++ b/tests/unit/pkgmgr/actions/mirror/test_remote_provision.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 import unittest
diff --git a/tests/unit/pkgmgr/actions/mirror/test_url_utils.py b/tests/unit/pkgmgr/actions/mirror/test_url_utils.py
index 3b1832b..8f5af1e 100644
--- a/tests/unit/pkgmgr/actions/mirror/test_url_utils.py
+++ b/tests/unit/pkgmgr/actions/mirror/test_url_utils.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 import unittest
diff --git a/tests/unit/pkgmgr/actions/release/test_files.py b/tests/unit/pkgmgr/actions/release/test_files.py
index 552a08a..328725b 100644
--- a/tests/unit/pkgmgr/actions/release/test_files.py
+++ b/tests/unit/pkgmgr/actions/release/test_files.py
@@ -37,7 +37,7 @@ class TestUpdatePyprojectVersion(unittest.TestCase):
 
             update_pyproject_version(path, "1.2.3", preview=False)
 
-            with open(path, "r", encoding="utf-8") as f:
+            with open(path, encoding="utf-8") as f:
                 content = f.read()
 
         self.assertIn('version = "1.2.3"', content)
@@ -62,7 +62,7 @@ class TestUpdatePyprojectVersion(unittest.TestCase):
 
             update_pyproject_version(path, "1.2.3", preview=True)
 
-            with open(path, "r", encoding="utf-8") as f:
+            with open(path, encoding="utf-8") as f:
                 content = f.read()
 
         self.assertEqual(content, original)
@@ -129,7 +129,7 @@ class TestUpdateFlakeVersion(unittest.TestCase):
 
             update_flake_version(path, "1.2.3", preview=False)
 
-            with open(path, "r", encoding="utf-8") as f:
+            with open(path, encoding="utf-8") as f:
                 content = f.read()
 
         self.assertIn('version = "1.2.3";', content)
@@ -144,7 +144,7 @@ class TestUpdateFlakeVersion(unittest.TestCase):
 
             update_flake_version(path, "1.2.3", preview=True)
 
-            with open(path, "r", encoding="utf-8") as f:
+            with open(path, encoding="utf-8") as f:
                 content = f.read()
 
         self.assertEqual(content, original)
@@ -170,7 +170,7 @@ class TestUpdatePkgbuildVersion(unittest.TestCase):
 
             update_pkgbuild_version(path, "1.2.3", preview=False)
 
-            with open(path, "r", encoding="utf-8") as f:
+            with open(path, encoding="utf-8") as f:
                 content = f.read()
 
         self.assertIn("pkgver=1.2.3", content)
@@ -196,7 +196,7 @@ class TestUpdatePkgbuildVersion(unittest.TestCase):
 
             update_pkgbuild_version(path, "1.2.3", preview=True)
 
-            with open(path, "r", encoding="utf-8") as f:
+            with open(path, encoding="utf-8") as f:
                 content = f.read()
 
         self.assertEqual(content, original)
@@ -222,7 +222,7 @@ class TestUpdateSpecVersion(unittest.TestCase):
 
             update_spec_version(path, "1.2.3", preview=False)
 
-            with open(path, "r", encoding="utf-8") as f:
+            with open(path, encoding="utf-8") as f:
                 content = f.read()
 
         self.assertIn("Version: 1.2.3", content)
@@ -249,7 +249,7 @@ class TestUpdateSpecVersion(unittest.TestCase):
 
             update_spec_version(path, "1.2.3", preview=True)
 
-            with open(path, "r", encoding="utf-8") as f:
+            with open(path, encoding="utf-8") as f:
                 content = f.read()
 
         self.assertEqual(content, original)
@@ -264,7 +264,7 @@ class TestUpdateChangelog(unittest.TestCase):
             update_changelog(path, "1.2.3", message="First release", preview=False)
 
             self.assertTrue(os.path.exists(path))
-            with open(path, "r", encoding="utf-8") as f:
+            with open(path, encoding="utf-8") as f:
                 content = f.read()
 
         # New file must lead with an H1 so markdownlint MD041 is happy.
@@ -280,7 +280,7 @@ class TestUpdateChangelog(unittest.TestCase):
 
             update_changelog(path, "1.0.0", message="Second release", preview=False)
 
-            with open(path, "r", encoding="utf-8") as f:
+            with open(path, encoding="utf-8") as f:
                 content = f.read()
 
         # H1 still on top, new entry above the existing one.
@@ -303,7 +303,7 @@ class TestUpdateChangelog(unittest.TestCase):
 
             update_changelog(path, "1.0.0", message=None, preview=False)
 
-            with open(path, "r", encoding="utf-8") as f:
+            with open(path, encoding="utf-8") as f:
                 content = f.read()
 
         # An H1 is added so MD041 is satisfied even for legacy files.
@@ -315,7 +315,7 @@ class TestUpdateChangelog(unittest.TestCase):
             path = os.path.join(tmpdir, "CHANGELOG.md")
             update_changelog(path, "1.2.3", message="* Provided bullet", preview=False)
 
-            with open(path, "r", encoding="utf-8") as f:
+            with open(path, encoding="utf-8") as f:
                 content = f.read()
 
         self.assertIn("\n\n* Provided bullet\n", content)
@@ -331,7 +331,7 @@ class TestUpdateChangelog(unittest.TestCase):
                 preview=False,
             )
 
-            with open(path, "r", encoding="utf-8") as f:
+            with open(path, encoding="utf-8") as f:
                 content = f.read()
 
         self.assertIn("**Summary**", content)
@@ -348,7 +348,7 @@ class TestUpdateChangelog(unittest.TestCase):
 
             update_changelog(path, "1.0.0", message="Preview only", preview=True)
 
-            with open(path, "r", encoding="utf-8") as f:
+            with open(path, encoding="utf-8") as f:
                 content = f.read()
 
         self.assertEqual(content, original)
@@ -374,7 +374,7 @@ class TestUpdateDebianChangelog(unittest.TestCase):
                     preview=False,
                 )
 
-            with open(path, "r", encoding="utf-8") as f:
+            with open(path, encoding="utf-8") as f:
                 content = f.read()
 
         self.assertIn("package-manager (1.2.3-1) unstable; urgency=medium", content)
@@ -402,7 +402,7 @@ class TestUpdateDebianChangelog(unittest.TestCase):
                     preview=True,
                 )
 
-            with open(path, "r", encoding="utf-8") as f:
+            with open(path, encoding="utf-8") as f:
                 content = f.read()
 
         self.assertEqual(content, original)
@@ -428,7 +428,7 @@ class TestUpdateDebianChangelog(unittest.TestCase):
                     preview=False,
                 )
 
-            with open(path, "r", encoding="utf-8") as f:
+            with open(path, encoding="utf-8") as f:
                 content = f.read()
 
         self.assertIn("  * First bullet", content)
@@ -484,7 +484,7 @@ class TestUpdateSpecChangelog(unittest.TestCase):
                     preview=False,
                 )
 
-            with open(path, "r", encoding="utf-8") as f:
+            with open(path, encoding="utf-8") as f:
                 content = f.read()
 
         self.assertIn("%changelog", content)
@@ -526,7 +526,7 @@ class TestUpdateSpecChangelog(unittest.TestCase):
                     preview=True,
                 )
 
-            with open(path, "r", encoding="utf-8") as f:
+            with open(path, encoding="utf-8") as f:
                 content = f.read()
 
         self.assertEqual(content, original)
@@ -567,7 +567,7 @@ class TestUpdateSpecChangelog(unittest.TestCase):
                     preview=False,
                 )
 
-            with open(path, "r", encoding="utf-8") as f:
+            with open(path, encoding="utf-8") as f:
                 content = f.read()
 
         self.assertIn("- * First bullet", content)
diff --git a/tests/unit/pkgmgr/actions/release/test_package_name.py b/tests/unit/pkgmgr/actions/release/test_package_name.py
index be761e0..1d24560 100644
--- a/tests/unit/pkgmgr/actions/release/test_package_name.py
+++ b/tests/unit/pkgmgr/actions/release/test_package_name.py
@@ -11,7 +11,6 @@ import os
 import tempfile
 import unittest
 from pathlib import Path
-from typing import Optional
 
 from pkgmgr.actions.release.package_name import resolve_package_name
 from pkgmgr.core.repository.paths import RepoPaths
@@ -20,9 +19,9 @@ from pkgmgr.core.repository.paths import RepoPaths
 def _paths(
     repo_dir: str,
     *,
-    debian_control: Optional[str] = None,
-    arch_pkgbuild: Optional[str] = None,
-    rpm_spec: Optional[str] = None,
+    debian_control: str | None = None,
+    arch_pkgbuild: str | None = None,
+    rpm_spec: str | None = None,
 ) -> RepoPaths:
     return RepoPaths(
         repo_dir=repo_dir,
diff --git a/tests/unit/pkgmgr/actions/repository/test_deinstall.py b/tests/unit/pkgmgr/actions/repository/test_deinstall.py
index 905ae62..ec05373 100644
--- a/tests/unit/pkgmgr/actions/repository/test_deinstall.py
+++ b/tests/unit/pkgmgr/actions/repository/test_deinstall.py
@@ -36,9 +36,7 @@ class TestDeinstallRepos(unittest.TestCase):
             def exists_side_effect(path):
                 if path == "/home/u/.local/bin/demo":
                     return True
-                if path == "/repos/github.com/alice/demo/Makefile":
-                    return True
-                return False
+                return path == "/repos/github.com/alice/demo/Makefile"
 
             mock_exists.side_effect = exists_side_effect
 
diff --git a/tests/unit/pkgmgr/cli/commands/test_release.py b/tests/unit/pkgmgr/cli/commands/test_release.py
index 522e524..ed0131d 100644
--- a/tests/unit/pkgmgr/cli/commands/test_release.py
+++ b/tests/unit/pkgmgr/cli/commands/test_release.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 Unit tests for pkgmgr.cli.commands.release.
 
@@ -16,7 +14,6 @@ from __future__ import annotations
 import argparse
 import unittest
 from types import SimpleNamespace
-from typing import List
 from unittest.mock import call, patch
 
 
@@ -25,7 +22,7 @@ class TestReleaseCommand(unittest.TestCase):
     Tests for the `pkgmgr release` CLI wiring.
     """
 
-    def _make_ctx(self, all_repos: List[dict]) -> SimpleNamespace:
+    def _make_ctx(self, all_repos: list[dict]) -> SimpleNamespace:
         """
         Create a minimal CLIContext-like object for tests.
 
@@ -39,7 +36,7 @@ class TestReleaseCommand(unittest.TestCase):
             user_config_path="/tmp/config.yaml",
         )
 
-    def _parse_release_args(self, argv: List[str]) -> argparse.Namespace:
+    def _parse_release_args(self, argv: list[str]) -> argparse.Namespace:
         """
         Build a real top-level parser and parse the given argv list
         to obtain the Namespace for the `release` command.
diff --git a/tests/unit/pkgmgr/cli/commands/test_repos.py b/tests/unit/pkgmgr/cli/commands/test_repos.py
index 2f32a21..85f8de6 100644
--- a/tests/unit/pkgmgr/cli/commands/test_repos.py
+++ b/tests/unit/pkgmgr/cli/commands/test_repos.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 Unit tests for pkgmgr.cli.commands.repos
 
@@ -26,17 +24,17 @@ import io
 import unittest
 from contextlib import redirect_stdout
 from types import SimpleNamespace
-from typing import Any, Dict, List
+from typing import Any
 from unittest.mock import patch
 
 from pkgmgr.cli.commands.repos import handle_repos_command
 from pkgmgr.cli.context import CLIContext
 
-Repository = Dict[str, Any]
+Repository = dict[str, Any]
 
 
 class TestReposCommand(unittest.TestCase):
-    def _make_ctx(self, repositories: List[Repository]) -> CLIContext:
+    def _make_ctx(self, repositories: list[Repository]) -> CLIContext:
         """
         Helper to build a minimal CLIContext for tests.
         """
@@ -57,7 +55,7 @@ class TestReposCommand(unittest.TestCase):
         When repository["directory"] is present, handle_repos_command("path")
         should print this value directly without calling get_repo_dir().
         """
-        repos: List[Repository] = [
+        repos: list[Repository] = [
             {
                 "provider": "github.com",
                 "account": "kevinveenbirkenbach",
@@ -93,7 +91,7 @@ class TestReposCommand(unittest.TestCase):
         should call get_repo_dir(ctx.repositories_base_dir, repo) and print
         the returned value.
         """
-        repos: List[Repository] = [
+        repos: list[Repository] = [
             {
                 "provider": "github.com",
                 "account": "kevinveenbirkenbach",
@@ -155,7 +153,7 @@ class TestReposCommand(unittest.TestCase):
         'shell' should resolve the repository directory and pass it as cwd
         to run_command(), along with the full shell command string.
         """
-        repos: List[Repository] = [
+        repos: list[Repository] = [
             {
                 "provider": "github.com",
                 "account": "kevinveenbirkenbach",
@@ -196,7 +194,7 @@ class TestReposCommand(unittest.TestCase):
         """
         'shell' without -c/--command should print an error and exit with code 2.
         """
-        repos: List[Repository] = []
+        repos: list[Repository] = []
         ctx = self._make_ctx(repos)
 
         args = SimpleNamespace(
diff --git a/tests/unit/pkgmgr/cli/commands/test_tools.py b/tests/unit/pkgmgr/cli/commands/test_tools.py
index 074fc93..061b26f 100644
--- a/tests/unit/pkgmgr/cli/commands/test_tools.py
+++ b/tests/unit/pkgmgr/cli/commands/test_tools.py
@@ -2,12 +2,12 @@ from __future__ import annotations
 
 import unittest
 from types import SimpleNamespace
-from typing import Any, Dict, List
+from typing import Any
 from unittest.mock import call, patch
 
 from pkgmgr.cli.commands.tools import handle_tools_command
 
-Repository = Dict[str, Any]
+Repository = dict[str, Any]
 
 
 class _Args:
@@ -29,7 +29,7 @@ class TestHandleToolsCommand(unittest.TestCase):
     """
 
     def setUp(self) -> None:
-        self.repos: List[Repository] = [
+        self.repos: list[Repository] = [
             {"alias": "repo1", "directory": "/tmp/repo1"},
             {"alias": "repo2", "directory": "/tmp/repo2"},
         ]
diff --git a/tests/unit/pkgmgr/cli/test_cli.py b/tests/unit/pkgmgr/cli/test_cli.py
index 5755fa5..1713230 100644
--- a/tests/unit/pkgmgr/cli/test_cli.py
+++ b/tests/unit/pkgmgr/cli/test_cli.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 """
 Unit tests for the pkgmgr CLI (version command).
 
@@ -23,13 +21,13 @@ import tempfile
 import textwrap
 import unittest
 from contextlib import redirect_stdout
-from typing import Any, Dict, List
+from typing import Any
 from unittest import mock
 
 from pkgmgr import cli
 
 
-def _fake_config() -> Dict[str, Any]:
+def _fake_config() -> dict[str, Any]:
     """
     Provide a minimal configuration dict sufficient for cli.main()
     to start without touching real config files.
@@ -132,7 +130,7 @@ class TestCliVersion(unittest.TestCase):
 
     def _run_cli_version_and_capture(
         self,
-        extra_args: List[str] | None = None,
+        extra_args: list[str] | None = None,
     ) -> str:
         """
         Run 'pkgmgr version [extra_args]' via cli.main() and return captured stdout.
diff --git a/tests/unit/pkgmgr/cli/test_handle_branch.py b/tests/unit/pkgmgr/cli/test_handle_branch.py
index 0e40a18..e78de46 100644
--- a/tests/unit/pkgmgr/cli/test_handle_branch.py
+++ b/tests/unit/pkgmgr/cli/test_handle_branch.py
@@ -45,7 +45,7 @@ class TestCliBranch(unittest.TestCase):
         handle_branch(args, ctx)
 
         mock_open_branch.assert_called_once()
-        call_args, call_kwargs = mock_open_branch.call_args
+        _call_args, call_kwargs = mock_open_branch.call_args
         self.assertEqual(call_kwargs.get("name"), "feature/cli-test")
         self.assertEqual(call_kwargs.get("base_branch"), "develop")
         self.assertEqual(call_kwargs.get("cwd"), ".")
diff --git a/tests/unit/pkgmgr/cli/tools/test_vscode.py b/tests/unit/pkgmgr/cli/tools/test_vscode.py
index 18d5803..338a484 100644
--- a/tests/unit/pkgmgr/cli/tools/test_vscode.py
+++ b/tests/unit/pkgmgr/cli/tools/test_vscode.py
@@ -5,10 +5,10 @@ import os
 import tempfile
 import unittest
 from types import SimpleNamespace
-from typing import Any, Dict, List
+from typing import Any
 from unittest.mock import patch
 
-Repository = Dict[str, Any]
+Repository = dict[str, Any]
 
 
 class TestOpenVSCodeWorkspace(unittest.TestCase):
@@ -27,13 +27,15 @@ class TestOpenVSCodeWorkspace(unittest.TestCase):
         from pkgmgr.cli.tools.vscode import open_vscode_workspace
 
         ctx = SimpleNamespace(config_merged={}, all_repositories=[])
-        selected: List[Repository] = [
+        selected: list[Repository] = [
             {"provider": "github.com", "account": "x", "repository": "y"}
         ]
 
-        with patch("pkgmgr.cli.tools.vscode.shutil.which", return_value=None):
-            with self.assertRaises(RuntimeError) as cm:
-                open_vscode_workspace(ctx, selected)
+        with (
+            patch("pkgmgr.cli.tools.vscode.shutil.which", return_value=None),
+            self.assertRaises(RuntimeError) as cm,
+        ):
+            open_vscode_workspace(ctx, selected)
 
         self.assertIn("VS Code CLI ('code') not found", str(cm.exception))
 
@@ -44,7 +46,7 @@ class TestOpenVSCodeWorkspace(unittest.TestCase):
             config_merged={"directories": {"workspaces": "~/Workspaces"}},
             all_repositories=[],
         )
-        selected: List[Repository] = [
+        selected: list[Repository] = [
             {"provider": "github.com", "account": "x", "repository": "y"}
         ]
 
@@ -74,7 +76,7 @@ class TestOpenVSCodeWorkspace(unittest.TestCase):
                 all_repositories=[],
                 repositories_base_dir=os.path.join(tmp, "Repos"),
             )
-            selected: List[Repository] = [
+            selected: list[Repository] = [
                 {
                     "provider": "github.com",
                     "account": "kevin",
@@ -101,7 +103,7 @@ class TestOpenVSCodeWorkspace(unittest.TestCase):
             workspace_file = os.path.join(workspaces_dir, "dotlinker.code-workspace")
             self.assertTrue(os.path.exists(workspace_file))
 
-            with open(workspace_file, "r", encoding="utf-8") as f:
+            with open(workspace_file, encoding="utf-8") as f:
                 data = json.load(f)
 
             self.assertEqual(data["folders"], [{"path": repo_path}])
@@ -125,7 +127,7 @@ class TestOpenVSCodeWorkspace(unittest.TestCase):
                 config_merged={"directories": {"workspaces": workspaces_dir}},
                 all_repositories=[],
             )
-            selected: List[Repository] = [
+            selected: list[Repository] = [
                 {
                     "provider": "github.com",
                     "account": "kevin",
@@ -149,7 +151,7 @@ class TestOpenVSCodeWorkspace(unittest.TestCase):
             ):
                 open_vscode_workspace(ctx, selected)
 
-            with open(workspace_file, "r", encoding="utf-8") as f:
+            with open(workspace_file, encoding="utf-8") as f:
                 data = json.load(f)
 
             self.assertEqual(data, original)
diff --git a/tests/unit/pkgmgr/core/command/test_resolve.py b/tests/unit/pkgmgr/core/command/test_resolve.py
index 17828b4..d562b67 100644
--- a/tests/unit/pkgmgr/core/command/test_resolve.py
+++ b/tests/unit/pkgmgr/core/command/test_resolve.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python3
+from __future__ import annotations
 
 import os
 import stat
diff --git a/tests/unit/pkgmgr/core/command/test_run.py b/tests/unit/pkgmgr/core/command/test_run.py
index c2c381c..f030020 100644
--- a/tests/unit/pkgmgr/core/command/test_run.py
+++ b/tests/unit/pkgmgr/core/command/test_run.py
@@ -33,9 +33,11 @@ class TestRunCommand(unittest.TestCase):
             "import sys; print('oops', file=sys.stderr); sys.exit(2)",
         ]
 
-        with patch.object(run_mod.sys, "exit", side_effect=SystemExit(2)) as exit_mock:
-            with self.assertRaises(SystemExit) as ctx:
-                run_mod.run_command(cmd, allow_failure=False)
+        with (
+            patch.object(run_mod.sys, "exit", side_effect=SystemExit(2)) as exit_mock,
+            self.assertRaises(SystemExit) as ctx,
+        ):
+            run_mod.run_command(cmd, allow_failure=False)
 
         self.assertEqual(ctx.exception.code, 2)
         exit_mock.assert_called_once_with(2)
diff --git a/tests/unit/pkgmgr/core/config/test_load.py b/tests/unit/pkgmgr/core/config/test_load.py
index 4dfb98b..8bb3c25 100644
--- a/tests/unit/pkgmgr/core/config/test_load.py
+++ b/tests/unit/pkgmgr/core/config/test_load.py
@@ -256,9 +256,11 @@ class LoadConfigIntegrationUnitTests(unittest.TestCase):
             )
 
             fake_pkgmgr = types.SimpleNamespace(__file__=str(pkg_root / "__init__.py"))
-            with patch.dict(sys.modules, {"pkgmgr": fake_pkgmgr}):
-                with patch.dict(os.environ, {"HOME": str(home)}):
-                    merged = load_config(user_config_path)
+            with (
+                patch.dict(sys.modules, {"pkgmgr": fake_pkgmgr}),
+                patch.dict(os.environ, {"HOME": str(home)}),
+            ):
+                merged = load_config(user_config_path)
 
             # directories are merged: defaults then user
             self.assertEqual(merged["directories"]["repositories"], "/PKG/Repos")
diff --git a/tests/unit/pkgmgr/core/git/queries/test_remote_check.py b/tests/unit/pkgmgr/core/git/queries/test_remote_check.py
index fe89eb7..01e653c 100644
--- a/tests/unit/pkgmgr/core/git/queries/test_remote_check.py
+++ b/tests/unit/pkgmgr/core/git/queries/test_remote_check.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 from __future__ import annotations
 
 import unittest
diff --git a/tests/unit/pkgmgr/core/git/test_run.py b/tests/unit/pkgmgr/core/git/test_run.py
index fce0f42..efd365c 100644
--- a/tests/unit/pkgmgr/core/git/test_run.py
+++ b/tests/unit/pkgmgr/core/git/test_run.py
@@ -38,9 +38,7 @@ class TestGitRun(unittest.TestCase):
         self.assertEqual(kwargs["cwd"], "/repo")
         self.assertTrue(kwargs["check"])
         self.assertTrue(kwargs["text"])
-        # ensure pipes are used (matches implementation intent)
-        self.assertIsNotNone(kwargs["stdout"])
-        self.assertIsNotNone(kwargs["stderr"])
+        self.assertTrue(kwargs["capture_output"])
 
     def test_failure_raises_giterror_with_details(self) -> None:
         # Build a CalledProcessError with stdout/stderr populated
@@ -57,9 +55,11 @@ class TestGitRun(unittest.TestCase):
         exc.stdout = "OUT!"
         exc.stderr = "ERR!"
 
-        with patch("pkgmgr.core.git.run.subprocess.run", side_effect=exc):
-            with self.assertRaises(GitRunError) as ctx:
-                run(["status"], cwd="/bad/repo", preview=False)
+        with (
+            patch("pkgmgr.core.git.run.subprocess.run", side_effect=exc),
+            self.assertRaises(GitRunError) as ctx,
+        ):
+            run(["status"], cwd="/bad/repo", preview=False)
 
         msg = str(ctx.exception)
         self.assertIn("Git command failed in '/bad/repo': git status", msg)
diff --git a/tests/unit/pkgmgr/core/remote_provisioning/test_visibility.py b/tests/unit/pkgmgr/core/remote_provisioning/test_visibility.py
index c2f2ca4..cf38c31 100644
--- a/tests/unit/pkgmgr/core/remote_provisioning/test_visibility.py
+++ b/tests/unit/pkgmgr/core/remote_provisioning/test_visibility.py
@@ -132,7 +132,7 @@ class TestSetRepoVisibility(unittest.TestCase):
 
         self.assertEqual(res.status, "updated")
         provider.set_repo_private.assert_called_once()
-        args, kwargs = provider.set_repo_private.call_args
+        _args, kwargs = provider.set_repo_private.call_args
         self.assertEqual(kwargs.get("private"), False)
 
     def test_provider_hint_overrides_registry_resolution(self) -> None:
diff --git a/tests/unit/pkgmgr/core/repository/test_ignored.py b/tests/unit/pkgmgr/core/repository/test_ignored.py
index 8255b13..09d844d 100644
--- a/tests/unit/pkgmgr/core/repository/test_ignored.py
+++ b/tests/unit/pkgmgr/core/repository/test_ignored.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 import unittest
 
 from pkgmgr.core.repository.ignored import filter_ignored
diff --git a/tests/unit/pkgmgr/core/repository/test_selected.py b/tests/unit/pkgmgr/core/repository/test_selected.py
index 66a39c6..bc6f9b3 100644
--- a/tests/unit/pkgmgr/core/repository/test_selected.py
+++ b/tests/unit/pkgmgr/core/repository/test_selected.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python3
+from __future__ import annotations
 
 import os
 import unittest
diff --git a/tests/unit/pkgmgr/core/test_create_ink.py b/tests/unit/pkgmgr/core/test_create_ink.py
index 4ff7605..6e2c58b 100644
--- a/tests/unit/pkgmgr/core/test_create_ink.py
+++ b/tests/unit/pkgmgr/core/test_create_ink.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 import unittest
 from unittest.mock import patch
 
diff --git a/tests/unit/pkgmgr/core/test_git_utils.py b/tests/unit/pkgmgr/core/test_git_utils.py
index 5884a93..5c08c52 100644
--- a/tests/unit/pkgmgr/core/test_git_utils.py
+++ b/tests/unit/pkgmgr/core/test_git_utils.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 import unittest
 from unittest.mock import patch
 
diff --git a/tests/unit/pkgmgr/core/test_versioning.py b/tests/unit/pkgmgr/core/test_versioning.py
index a72a2cd..e1762e6 100644
--- a/tests/unit/pkgmgr/core/test_versioning.py
+++ b/tests/unit/pkgmgr/core/test_versioning.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-
 import unittest
 
 from pkgmgr.core.version.semver import (