ci(release): replace softprops/action-gh-release with gh CLI

Org GitHub Actions allowlist blocks softprops/action-gh-release@v2,
which made the v0.5.1 release run fail before any step executed.
Switch to the runner's bundled gh CLI to avoid the third-party action
and make the release upload idempotent: if the tag already has a
release we re-upload the asset with --clobber, otherwise we create a
new release with generated notes.

Also add .worktrees/ to .gitignore so locally created worktrees stay
untracked.

Author: heath-s

.github/workflows/release.yml

@@ -62,9 +62,19 @@ jobs:
         run: bun run scripts/prepare-macos-release-bundle.mjs
 
       - name: Create GitHub release and upload app bundle zip
-        uses: softprops/action-gh-release@v2
-        with:
-          tag_name: v${{ steps.version.outputs.version }}
-          name: v${{ steps.version.outputs.version }}
-          generate_release_notes: true
-          files: release/Stave-macOS.zip
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          set -euo pipefail
+          TAG="v${{ steps.version.outputs.version }}"
+          ASSET="release/Stave-macOS.zip"
+          if gh release view "$TAG" >/dev/null 2>&1; then
+            echo "Release $TAG already exists; updating asset."
+            gh release upload "$TAG" "$ASSET" --clobber
+          else
+            echo "Creating release $TAG."
+            gh release create "$TAG" \
+              --title "$TAG" \
+              --generate-notes \
+              "$ASSET"
+          fi

.gitignore

@@ -32,3 +32,6 @@ tests/artifacts/
 debug/
 ideas/
 ref/
+
+# git worktrees
+.worktrees/