Fix branch verification in release workflow

Use -a flag to include remote branches (origin/main) since
GitHub Actions checkout leaves repo in detached HEAD state.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: nogo

.github/workflows/release.yml

@@ -21,7 +21,7 @@ jobs:
         env:
           TAG_NAME: ${{ github.ref_name }}
         run: |
-          git branch --contains "$TAG_NAME" | grep -q 'main' || {
+          git branch -a --contains "$TAG_NAME" | grep -qE '(^|\/)main$' || {
             echo "Error: Tag $TAG_NAME is not on main branch"
             exit 1
           }