Add bakery.toml and packaging/arch to match bread ecosystem

Mirrors the build/distribution pattern used by the bread project:
- bakery.toml describes bos-settings as a bakery-managed package
- packaging/arch/PKGBUILD builds and installs the binary via cargo
- packaging/arch/bos-settings.desktop for app launchers
- LICENSE (MIT) required by PKGBUILD

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packaging/arch/PKGBUILD

@@ -0,0 +1,34 @@
+# Maintainer: Breadway <rileyhorsham@gmail.com>
+
+pkgname=bos-settings
+pkgver=0.1.0
+pkgrel=1
+pkgdesc="System settings app for Bread OS"
+arch=('x86_64')
+url="https://github.com/Breadway/bos"
+license=('MIT')
+depends=('gtk4' 'glib2' 'hicolor-icon-theme')
+optdepends=(
+  'snapper: snapshot management view'
+)
+makedepends=('rust' 'cargo')
+source=("${pkgname}-${pkgver}.tar.gz")
+sha256sums=('SKIP')
+
+build() {
+  cd "${srcdir}/${pkgname}-${pkgver}"
+  cargo build --release --locked -p bos-settings
+}
+
+check() {
+  cd "${srcdir}/${pkgname}-${pkgver}"
+  cargo test --release --locked -p bos-settings
+}
+
+package() {
+  cd "${srcdir}/${pkgname}-${pkgver}"
+  install -Dm755 target/release/bos-settings "${pkgdir}/usr/bin/bos-settings"
+  install -Dm644 packaging/arch/bos-settings.desktop \
+    "${pkgdir}/usr/share/applications/bos-settings.desktop"
+  install -Dm644 LICENSE "${pkgdir}/usr/share/licenses/${pkgname}/LICENSE"
+}