fix(ci): force-add gitignored ref-proj in upstream monitor

ref-proj/ is in .gitignore, so git add refuses it without -f. Same fix
as applied to upstream-sync.yml for OperationConfig.json.

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

Author: doublegate

.github/workflows/upstream-monitor.yml

@@ -275,7 +275,7 @@ jobs:
         run: |
           git config user.name "github-actions[bot]"
           git config user.email "github-actions[bot]@users.noreply.github.com"
-          git add ref-proj/CyberChef
+          git add -f ref-proj/CyberChef
           git commit -m "chore(upstream): update ref-proj/CyberChef to latest upstream" || echo "No changes to commit"
           git push origin master || echo "Nothing to push"