Add release pipeline: AUR packaging, Gitea workflow, MIT license

Mirrors the gpupaper release convention: v* tags build x86_64/aarch64
tarballs (binary + leptos site + systemd unit), upload them as Gitea
release assets, push bendik/cnats to Docker Hub, and update the AUR
package with checksums from the release assets.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

aur/PKGBUILD

@@ -0,0 +1,34 @@
+# Maintainer: Bendik Aagaard Lynghaug <bendik.lynghaug@gmail.com>
+pkgname=cnats
+pkgver=0.1.0
+pkgrel=1
+pkgdesc="Web chat over NATS subjects with Kanidm SSO (Leptos SSR)"
+arch=('x86_64' 'aarch64')
+url="https://prosjekt.klingenbergbygg.no/bl/cnats"
+license=('MIT')
+depends=('glibc' 'gcc-libs')
+optdepends=(
+    'nats-server: local message bus'
+    'postgresql: local message history archive'
+)
+provides=('cnats')
+conflicts=('cnats-git' 'cnats-bin')
+backup=('etc/cnats/env')
+source_x86_64=("cnats-v${pkgver}-x86_64.tar.gz::https://prosjekt.klingenbergbygg.no/bl/cnats/releases/download/v${pkgver}/cnats-v${pkgver}-x86_64.tar.gz")
+source_aarch64=("cnats-v${pkgver}-aarch64.tar.gz::https://prosjekt.klingenbergbygg.no/bl/cnats/releases/download/v${pkgver}/cnats-v${pkgver}-aarch64.tar.gz")
+sha256sums_x86_64=('SKIP')
+sha256sums_aarch64=('SKIP')
+
+package() {
+    install -Dm755 cnats "$pkgdir/usr/bin/cnats"
+
+    # Hydration wasm/js + css served by the binary (LEPTOS_SITE_ROOT).
+    install -dm755 "$pkgdir/usr/share/cnats"
+    cp -r site "$pkgdir/usr/share/cnats/site"
+
+    install -Dm644 cnats.service "$pkgdir/usr/lib/systemd/system/cnats.service"
+    install -Dm600 cnats.env "$pkgdir/etc/cnats/env"
+
+    install -Dm644 LICENSE "$pkgdir/usr/share/licenses/$pkgname/LICENSE"
+    install -Dm644 README.md "$pkgdir/usr/share/doc/$pkgname/README.md"
+}