Fix checkout to use head_ref for PRs

gitea.ref_name returns PR number for pull_request events, need to
use gitea.head_ref to get the actual branch name.

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

.forgejo/workflows/test.yaml

@@ -12,7 +12,9 @@ jobs:
     steps:
       - name: Checkout (git clone)
         run: |
-          git clone --depth 1 --branch "${{ gitea.ref_name }}" \
+          # For PRs use head_ref (branch name), for pushes use ref_name
+          BRANCH="${{ gitea.head_ref || gitea.ref_name }}"
+          git clone --depth 1 --branch "$BRANCH" \
             "${{ gitea.server_url }}/${{ gitea.repository }}.git" .
         env:
           GIT_SSL_NO_VERIFY: "true"
@@ -22,5 +24,6 @@ jobs:
           echo "Hello from Forgejo Actions!"
           echo "Runner: $(hostname)"
           echo "Repository: ${{ gitea.repository }}"
-          echo "Branch: ${{ gitea.ref_name }}"
+          echo "Event: ${{ gitea.event_name }}"
+          echo "Ref: ${{ gitea.ref }}"
           ls -la