feat(release): add packaging support for Arch, Debian, and RPM

* Implement Arch package build process in release workflow
* Add Debian and RPM packaging specifications
* Include man page installation in Makefile
* Create unitdore man page for documentation

pkg/arch/PKGBUILD

@@ -0,0 +1,44 @@
+# Maintainer: Hein (Warky Devs) <hein@warky.dev>
+pkgname=unitdore
+pkgver=0.1.0
+pkgrel=1
+pkgdesc="A door you open and close for container units — manage containers via systemd"
+arch=('x86_64' 'aarch64')
+url="https://warky.dev"
+license=('MIT')
+depends=('systemd')
+optdepends=(
+    'podman: Podman container runtime support'
+    'docker: Docker container runtime support'
+)
+makedepends=('go')
+backup=('etc/unitdore/units.yaml')
+source=("$pkgname-$pkgver.tar.gz::$url/archive/v$pkgver.tar.gz")
+sha256sums=('SKIP')
+
+build() {
+    cd "$pkgname"
+    export CGO_ENABLED=0
+    go build \
+        -trimpath \
+        -ldflags "-X main.version=$pkgver" \
+        -o "$pkgname" .
+}
+
+check() {
+    cd "$pkgname"
+    go test ./...
+}
+
+package() {
+    cd "$pkgname"
+
+    # Binary
+    install -Dm755 "$pkgname" "$pkgdir/usr/bin/$pkgname"
+
+    # Man page
+    install -Dm644 docs/unitdore.1 "$pkgdir/usr/share/man/man1/unitdore.1"
+
+    # Default config dir
+    install -dm755 "$pkgdir/etc/unitdore"
+}