feat(ci): stabilize virgin Arch tests with Makefile install/setup and Nix Git safety

* Switch virgin root/user workflows to use *make install* + *make setup/setup-venv*
* Add Git *safe.directory /src* to avoid flake evaluation failures on mounted repos
* Enable Nix flake run in workflows and prepare */nix* for non-root execution
* Refactor Arch packaging to build in an isolated */tmp* directory via *aur_builder*
* Rename installer scripts (*run-** → *dependencies.sh* / *package.sh*) and adjust Docker entry + env var to *REINSTALL_PKGMGR*

https://chatgpt.com/share/693c29d9-9b28-800f-a549-5661c783d968

scripts/installation/main.sh

@@ -1,87 +1,15 @@
 #!/usr/bin/env bash
 set -euo pipefail
 
-# ------------------------------------------------------------
-# main.sh
-#
-# Developer / system setup entrypoint.
-#
-# Responsibilities:
-#   - If inside a Nix shell (IN_NIX_SHELL=1):
-#       * Skip venv creation and dependency installation
-#       * Run `python3 main.py install`
-#   - If running as root (EUID=0):
-#       * Run system-level installer (run-package.sh)
-#   - Otherwise (normal user):
-#       * Create ~/.venvs/pkgmgr virtual environment if missing
-#       * Install Python dependencies into that venv
-#       * Append auto-activation to ~/.bashrc and ~/.zshrc
-#       * Run `main.py install` using the venv Python
-# ------------------------------------------------------------
-
-echo "[installation/main] Starting setup..."
-
-PROJECT_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
-cd "${PROJECT_ROOT}"
-
-VENV_DIR="${HOME}/.venvs/pkgmgr"
-RC_LINE='if [ -d "${HOME}/.venvs/pkgmgr" ]; then . "${HOME}/.venvs/pkgmgr/bin/activate"; if [ -n "${PS1:-}" ]; then echo "Global Python virtual environment '\''~/.venvs/pkgmgr'\'' activated."; fi; fi'
-
-# ------------------------------------------------------------
-# 1) Nix shell mode: do not touch venv, only run main.py install
-# ------------------------------------------------------------
-if [[ -n "${IN_NIX_SHELL:-}" ]]; then
-    echo "[installation/main] Nix shell detected (IN_NIX_SHELL=1)."
-    echo "[installation/main] Skipping virtualenv creation and dependency installation."
-    echo "[installation/main] Running main.py install via system python3..."
-    python3 main.py install
-    echo "[installation/main] Setup finished (Nix mode)."
-    exit 0
+if [[ "${EUID:-$(id -u)}" -ne 0 ]]; then
+  echo "[installation/install] Warning: Installation is just possible via root."
+  exit 0
 fi
 
-# ------------------------------------------------------------
-# 2) Root mode: system / distro-level installation
-# ------------------------------------------------------------
-if [[ "${EUID:-$(id -u)}" -eq 0 ]]; then
-    echo "[installation/main] Running as root (EUID=0)."
-    echo "[installation/main] Skipping user virtualenv and shell RC modifications."
-    echo "[installation/main] Delegating to scripts/installation/run-package.sh..."
-    bash scripts/installation/run-package.sh
-    echo "[installation/main] Root/system setup complete."
-    exit 0
-fi
-
-# ------------------------------------------------------------
-# 3) Normal user mode: dev setup with venv
-# ------------------------------------------------------------
-
-echo "[installation/main] Running in normal user mode (developer setup)."
-
-echo "[installation/main] Ensuring main.py is executable..."
-chmod +x main.py || true
-
-echo "[installation/main] Ensuring global virtualenv root: ${HOME}/.venvs"
-mkdir -p "${HOME}/.venvs"
-
-echo "[installation/main] Creating/updating virtualenv via helper..."
-PKGMGR_VENV_DIR="${VENV_DIR}" bash scripts/installation/venv-create.sh
-
-echo "[installation/main] Ensuring ~/.bashrc and ~/.zshrc exist..."
-touch "${HOME}/.bashrc" "${HOME}/.zshrc"
-
-echo "[installation/main] Ensuring venv auto-activation is present in shell rc files..."
-for rc in "${HOME}/.bashrc" "${HOME}/.zshrc"; do
-    if ! grep -qxF "${RC_LINE}" "$rc"; then
-        echo "${RC_LINE}" >> "$rc"
-        echo "[installation/main] Appended auto-activation to $rc"
-    else
-        echo "[installation/main] Auto-activation already present in $rc"
-    fi
-done
-
-echo "[installation/main] Running main.py install via venv Python..."
-"${VENV_DIR}/bin/python" main.py install
-
-echo
-echo "[installation/main] Developer setup complete."
-echo "Restart your shell (or run 'exec bash' or 'exec zsh') to activate the environment."
+echo "[installation] Running as root (EUID=0)."
+echo "[installation] Install Package Dependencies..."
+bash  scripts/installation/dependencies.sh
+echo "[installation] Install Distribution Package..."
+bash scripts/installation/package.sh
+echo "[installation] Root/system setup complete."
+exit 0