ci: add workflow_dispatch trigger to Quality Gates for promotion CI

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Frank Steiler

.github/workflows/ci.yml

@@ -3,6 +3,7 @@ name: Quality Gates
 on:
   pull_request:
     branches: [main, beta]
+  workflow_dispatch:
 
 concurrency:
   group: ci-${{ github.ref }}