ci(release): attach source archives to release and use them for AUR package

Gitea's /archive/ endpoint is disabled, which broke the AUR source download.
Build source tar.gz/zip with git archive, upload as release assets, and point
the PKGBUILD and checksum step at the release asset.

.gitea/workflows/release.yml

@@ -53,6 +53,13 @@ jobs:
             echo "Built $NAME"
           done
 
+      - name: Build source archives
+        run: |
+          TAG="${{ github.event.inputs.tag || github.ref_name }}"
+          PREFIX="unitdore-${TAG#v}"
+          git archive --format=tar.gz --prefix="${PREFIX}/" -o "unitdore-${TAG}-source.tar.gz" "$TAG"
+          git archive --format=zip    --prefix="${PREFIX}/" -o "unitdore-${TAG}-source.zip"    "$TAG"
+
       - name: Create release and upload assets
         run: |
           TAG="${{ github.event.inputs.tag || github.ref_name }}"
@@ -166,7 +173,7 @@ jobs:
           echo "Publishing AUR package version ${PKGVER}-${PKGREL}"
 
           # Compute SHA256 of the source archive from the same URL the PKGBUILD will download.
-          SHA=$(curl -fsSL "https://git.warky.dev/wdevs/unitdore/archive/v${PKGVER}.zip" | sha256sum | cut -d' ' -f1)
+          SHA=$(curl -fsSL "https://git.warky.dev/wdevs/unitdore/releases/download/v${PKGVER}/unitdore-v${PKGVER}-source.zip" | sha256sum | cut -d' ' -f1)
 
           # Update PKGBUILD — keep remote source URL, bump version/checksum, and increment pkgrel for same-version rebuilds.
           sed -e "s/^pkgver=.*/pkgver=${PKGVER}/" \