Refine packaging layout and Arch build paths

* Move Arch-specific ignore rules into `packaging/arch/.gitignore` and simplify top-level `.gitignore`/`.dockerignore`.
* Update Arch `PKGBUILD` to sync from the project root and drop `packaging/` from the installed tree.
* Fix OS-specific `package.sh` helpers to resolve the new `packaging/*` locations correctly for Arch, Debian/Ubuntu, Fedora, and CentOS.

packaging/arch/.gitignore

@@ -0,0 +1,6 @@
+# Arch pkg artifacts
+*.pkg.tar.*
+*.log
+package-manager-*
+src/
+pkg/

packaging/arch/PKGBUILD

@@ -15,7 +15,7 @@ makedepends=('rsync')
 install=${pkgname}.install
 
 # Local source checkout — avoids the tarball requirement.
-# This assumes you build the package from inside the main project repository.
+# We build from the project root (two levels above packaging/arch/).
 source=()
 sha256sums=()
 
@@ -24,12 +24,17 @@ _srcdir_name="source"
 
 prepare() {
   mkdir -p "$srcdir/$_srcdir_name"
+
+  local project_root
+  project_root="$(cd "$startdir/../.." && pwd)"
+
   rsync -a \
     --exclude=".git" \
     --exclude=".github" \
     --exclude="pkg" \
     --exclude="srcpkg" \
-    "$startdir/" "$srcdir/$_srcdir_name/"
+    --exclude="packaging" \
+    "$project_root/" "$srcdir/$_srcdir_name/"
 }
 
 build() {
@@ -62,7 +67,8 @@ package() {
     "$pkgdir/usr/lib/package-manager/PKGBUILD" \
     "$pkgdir/usr/lib/package-manager/Dockerfile" \
     "$pkgdir/usr/lib/package-manager/debian" \
+    "$pkgdir/usr/lib/package-manager/packaging" \
     "$pkgdir/usr/lib/package-manager/.gitignore" \
     "$pkgdir/usr/lib/package-manager/__pycache__" \
-    "$pkgdir/usr/lib/package-manager/.gitkeep"
+    "$pkgdir/usr/lib/package-manager/.gitkeep" || true
 }

packaging/arch/src/source/PKGBUILD

@@ -0,0 +1,68 @@
+# Maintainer: Kevin Veen-Birkenbach <info@veen.world>
+
+pkgname=package-manager
+pkgver=0.9.1
+pkgrel=1
+pkgdesc="Local-flake wrapper for Kevin's package-manager (Nix-based)."
+arch=('any')
+url="https://github.com/kevinveenbirkenbach/package-manager"
+license=('MIT')
+
+# Nix is the only runtime dependency; Python is provided by the Nix closure.
+depends=('nix')
+makedepends=('rsync')
+
+install=${pkgname}.install
+
+# Local source checkout — avoids the tarball requirement.
+# This assumes you build the package from inside the main project repository.
+source=()
+sha256sums=()
+
+# Local source directory name under $srcdir
+_srcdir_name="source"
+
+prepare() {
+  mkdir -p "$srcdir/$_srcdir_name"
+  rsync -a \
+    --exclude=".git" \
+    --exclude=".github" \
+    --exclude="pkg" \
+    --exclude="srcpkg" \
+    "$startdir/" "$srcdir/$_srcdir_name/"
+}
+
+build() {
+  cd "$srcdir/$_srcdir_name"
+  :
+}
+
+package() {
+  cd "$srcdir/$_srcdir_name"
+
+  # Install the wrapper into /usr/bin
+  install -Dm0755 "scripts/pkgmgr-wrapper.sh" \
+    "$pkgdir/usr/bin/pkgmgr"
+
+  # Install Nix init helper
+  install -Dm0755 "scripts/init-nix.sh" \
+    "$pkgdir/usr/lib/package-manager/init-nix.sh"
+
+  # Install the full repository into /usr/lib/package-manager
+  mkdir -p "$pkgdir/usr/lib/package-manager"
+
+  # Copy entire project tree from our local source checkout
+  cp -a . "$pkgdir/usr/lib/package-manager/"
+
+  # Remove packaging-only and development artefacts from the installed tree
+  rm -rf \
+    "$pkgdir/usr/lib/package-manager/.git" \
+    "$pkgdir/usr/lib/package-manager/.github" \
+    "$pkgdir/usr/lib/package-manager/tests" \
+    "$pkgdir/usr/lib/package-manager/PKGBUILD" \
+    "$pkgdir/usr/lib/package-manager/Dockerfile" \
+    "$pkgdir/usr/lib/package-manager/debian" \
+    "$pkgdir/usr/lib/package-manager/.gitignore" \
+    "$pkgdir/usr/lib/package-manager/__pycache__" \
+    "$pkgdir/usr/lib/package-manager/.gitkeep"
+}

packaging/arch/src/source/package-manager.install

@@ -0,0 +1,11 @@
+post_install() {
+  /usr/lib/package-manager/init-nix.sh || true
+}
+
+post_upgrade() {
+  /usr/lib/package-manager/init-nix.sh || true
+}
+
+post_remove() {
+  echo ">>> package-manager removed. Nix itself was not removed."
+}