feat: fade-in animation, PKGBUILD for system installation

- CSS opacity transition (350ms ease-in) for panel and wallpaper
- PKGBUILD for makepkg/pacman installation
- .gitignore for makepkg build artifacts

pkg/PKGBUILD

@@ -0,0 +1,47 @@
+# ABOUTME: PKGBUILD for Moonset — Wayland session power menu.
+# ABOUTME: Builds from git source with automatic version detection.
+
+# Maintainer: Dominik Kressler
+
+pkgname=moonset-git
+pkgver=0.1.0.r6.g63bd7cf
+pkgrel=1
+pkgdesc="A Wayland session power menu with GTK4 and Layer Shell"
+arch=('any')
+url="https://gitea.moonarch.de/nevaforget/moonset"
+license=('MIT')
+depends=(
+    'python'
+    'python-gobject'
+    'gtk4'
+    'gtk4-layer-shell'
+)
+makedepends=(
+    'git'
+    'python-build'
+    'python-installer'
+    'python-hatchling'
+)
+provides=('moonset')
+conflicts=('moonset')
+source=("git+${url}.git")
+sha256sums=('SKIP')
+
+pkgver() {
+    cd "$srcdir/moonset"
+    git describe --long --tags | sed 's/^v//;s/-/.r/;s/-/./'
+}
+
+build() {
+    cd "$srcdir/moonset"
+    rm -rf dist/
+    python -m build --wheel --no-isolation
+}
+
+package() {
+    cd "$srcdir/moonset"
+    python -m installer --destdir="$pkgdir" dist/*.whl
+
+    # Example config
+    install -Dm644 config/moonset.toml "$pkgdir/etc/moonset/moonset.toml.example"
+}