fix(ci): unsigned desktop build must disable updater artifacts

createUpdaterArtifacts:true (for release.yml's .sig signing) makes `tauri build`
demand TAURI_SIGNING_PRIVATE_KEY and fail without it — even though the .deb/.AppImage
built fine. Override it off for the unsigned per-commit build via
--config '{"bundle":{"createUpdaterArtifacts":false}}'. release.yml keeps signing.

Claude-Session: https://claude.ai/code/session_01Xcm6ikLgGoCxxHrxtjkk5V

.gitea/workflows/build-desktop.yml

@@ -68,10 +68,16 @@ jobs:
         run: pnpm install --frozen-lockfile
 
       - name: Build desktop bundle (.deb + .AppImage)
-        # Unsigned — no TAURI_SIGNING_* needed here (this is a test artifact, not an
-        # updater release). --bundles restricts to the two installers we ship; tauri
-        # builds the web SPA first (beforeBuildCommand), so the desktop UI matches.
-        run: pnpm --filter @parking/desktop bundle --bundles deb,appimage
+        # Unsigned — no TAURI_SIGNING_* here (this is a test artifact, not an updater
+        # release). The config sets createUpdaterArtifacts:true (release.yml signs them),
+        # which makes tauri DEMAND the signing key and fail without it — so override it to
+        # false for this build via --config (a JSON patch merged over tauri.conf.json).
+        # --bundles restricts to the two installers we ship; tauri builds the web SPA
+        # first (beforeBuildCommand), so the desktop UI matches.
+        run: >
+          pnpm --filter @parking/desktop bundle
+          --bundles deb,appimage
+          --config '{"bundle":{"createUpdaterArtifacts":false}}'
 
       - name: Collect installers
         id: collect