style: autoformat src and tests

Repository-wide formatting pass over src/ and tests/: sorted imports and
__all__ entries, dropped redundant `# -*- coding: utf-8 -*-` headers,
unquoted forward-reference annotations (safe under
`from __future__ import annotations`), merged nested `with` statements,
moved `Iterable` and friends from `typing` to `collections.abc`, and
removed `# noqa: F401` markers that no longer suppress anything.

No behavioural changes. Unit and integration suites show the same four
pre-existing failures before and after the pass.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

tests/integration/test_branch_cli.py

@@ -1,5 +1,4 @@
 #!/usr/bin/env python3
-# -*- coding: utf-8 -*-
 
 """
 Integration tests for the `pkgmgr branch` CLI wiring.
@@ -16,8 +15,8 @@ from __future__ import annotations
 import unittest
 from unittest.mock import patch
 
-from pkgmgr.cli.parser import create_parser
 from pkgmgr.cli.commands.branch import handle_branch
+from pkgmgr.cli.parser import create_parser
 
 
 class TestBranchCLI(unittest.TestCase):

tests/integration/test_config_defaults_integration.py

@@ -11,8 +11,8 @@ from unittest.mock import patch
 
 import yaml
 
-from pkgmgr.core.config.load import load_config
 from pkgmgr.cli.commands import config as config_cmd
+from pkgmgr.core.config.load import load_config
 
 
 class ConfigDefaultsIntegrationTest(unittest.TestCase):

tests/integration/test_install_repos.py

@@ -1,5 +1,4 @@
 #!/usr/bin/env python3
-# -*- coding: utf-8 -*-
 
 import os
 import tempfile

tests/integration/test_mirror_commands.py

@@ -1,5 +1,4 @@
 #!/usr/bin/env python3
-# -*- coding: utf-8 -*-
 
 """
 CLI integration tests for `pkgmgr mirror`.

tests/integration/test_mirror_probe_detail_and_provision.py

@@ -1,5 +1,4 @@
 #!/usr/bin/env python3
-# -*- coding: utf-8 -*-
 
 """
 Integration test for mirror probing + provisioning after refactor.

tests/integration/test_recursive_capabilities.py

@@ -1,5 +1,4 @@
 #!/usr/bin/env python3
-# -*- coding: utf-8 -*-
 
 """
 Integration tests for recursive capability resolution and installer shadowing.
@@ -17,7 +16,8 @@ import os
 import shutil
 import tempfile
 import unittest
-from typing import List, Sequence, Tuple
+from collections.abc import Sequence
+from typing import List, Tuple
 from unittest.mock import patch
 
 import pkgmgr.actions.install as install_mod
@@ -29,7 +29,6 @@ from pkgmgr.actions.install.installers.os_packages.arch_pkgbuild import (
 )
 from pkgmgr.actions.install.installers.python import PythonInstaller
 
-
 InstallerSpec = Tuple[str, object]
 
 

tests/integration/test_update_silent_continues.py

@@ -1,5 +1,4 @@
 #!/usr/bin/env python3
-# -*- coding: utf-8 -*-
 
 from __future__ import annotations
 
@@ -42,7 +41,6 @@ class TestUpdateSilentContinues(unittest.TestCase):
             pull_calls.append(repo["repository"])
             if repo["repository"] == "repo-a":
                 raise SystemExit(2)
-            return None
 
         def install_side_effect(selected_repos, *_args, **kwargs):
             repo = selected_repos[0]
@@ -51,7 +49,6 @@ class TestUpdateSilentContinues(unittest.TestCase):
             )
             if repo["repository"] == "repo-b":
                 raise SystemExit(3)
-            return None
 
         # Patch at the exact import locations used inside UpdateManager.run()
         with (

tests/integration/test_visibility_integration.py

@@ -14,7 +14,6 @@ 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]