fix(ci): absolute manifest path for jprm and stable release download URL

jprm rejects a bare file name as repository path (it checks the directory
"" for existence). The asset upload answers with an /attachments/<uuid>
link; the manifest now uses /releases/download/<tag>/<file> instead.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.gitea/workflows/release.yaml

@@ -134,8 +134,10 @@ jobs:
             curl -fsS -X DELETE "${auth[@]}" "$api/releases/$release_id/assets/$asset_id"
           done
 
-          asset=$(curl -fsS -X POST "${auth[@]}" -F "attachment=@$ZIP" "$api/releases/$release_id/assets?name=$ASSET")
-          url=$(printf '%s' "$asset" | json 'print(data["browser_download_url"])')
+          curl -fsS -X POST "${auth[@]}" -F "attachment=@$ZIP" "$api/releases/$release_id/assets?name=$ASSET" > /dev/null
+
+          # The upload answers with an /attachments/<uuid> link; the release download URL is stable and readable.
+          url="$GITHUB_SERVER_URL/$GITHUB_REPOSITORY/releases/download/$GITHUB_REF_NAME/$ASSET"
           echo "Release-Asset: $url"
           echo "url=$url" >> "$GITHUB_OUTPUT"
 
@@ -155,7 +157,8 @@ jobs:
           cd "$workdir"
           [ -f manifest.json ] || echo '[]' > manifest.json
           # Adds the version in front (sorted descending) and keeps older versions; MD5 of the ZIP as checksum.
-          /opt/jprm/bin/jprm repo add manifest.json "$ZIP" --plugin-url "$URL"
+          # jprm needs an absolute path: for a bare file name it checks the directory "" and fails.
+          /opt/jprm/bin/jprm repo add "$workdir/manifest.json" "$ZIP" --plugin-url "$URL"
           git add manifest.json
           if git diff --cached --quiet; then
             echo "manifest.json unverändert"