packaging: PKGBUILD, changelog and tag-driven release workflow (0.4.0)

Same shape as uhhm/gdo: a v* tag runs makepkg on the x86_64 (ergo,
"bare") and aarch64 (klokka) runners, uploads to the [uhhm] Arch
registry under namespace bl, and creates a release with the changelog
section as notes. The tag must agree with PKGBUILD's pkgver and
Cargo.toml's version. Without a REGISTRY_TOKEN secret the publish step
warns and skips so the build is still verified.

Version jumps to 0.4.0 because upstream already tagged v0.2.1 and
v0.3.0 on this history before the rewrite reset Cargo.toml to 0.2.0.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

PKGBUILD

@@ -0,0 +1,40 @@
+# Maintainer: Bendik Aagaard Lynghaug <bendik.lynghaug@gmail.com>
+# Built from the tagged checkout by .gitea/workflows/release.yml, once
+# per architecture, and uploaded to the [uhhm] registry on
+# project.uhhm.no (namespace bl). pkgver is the version; the tag has
+# to agree with it and with Cargo.toml.
+pkgname=wldash
+pkgver=0.4.0
+pkgrel=1
+pkgdesc="Dashboard/launcher/control-panel for wlroots-style Wayland compositors (layer-shell)"
+arch=('x86_64' 'aarch64')
+url="https://project.uhhm.no/bl/wldash"
+license=('GPL-3.0-only')
+depends=('glibc' 'gcc-libs' 'dbus' 'libpulse' 'libxkbcommon' 'fontconfig' 'wayland')
+makedepends=('cargo')
+optdepends=('upower: battery widget'
+            'pipewire-pulse: volume widget (or pulseaudio)')
+# !lto: Cargo.toml already does lto = "fat"; makepkg's -flto in RUSTFLAGS
+# would only fight it. !debug: panic = "abort" release, nothing to strip.
+options=('!debug' '!lto')
+
+# Sources are the checkout itself: makepkg resolves local sources by
+# basename next to the PKGBUILD, so the tagged tree CI builds from is
+# the source of truth, as in uhhm/gdo.
+
+build() {
+    cd "$startdir"
+    cargo build --release --locked
+}
+
+check() {
+    cd "$startdir"
+    cargo test --release --locked
+}
+
+package() {
+    cd "$startdir"
+    install -Dm755 "${CARGO_TARGET_DIR:-target}/release/wldash" "$pkgdir/usr/bin/wldash"
+    install -Dm644 README.md "$pkgdir/usr/share/doc/$pkgname/README.md"
+    install -Dm644 LICENSE "$pkgdir/usr/share/licenses/$pkgname/LICENSE"
+}