Restrict Playwright workflow to master branch with manual trigger option

- Remove automatic PR trigger to prevent running on all pull requests
- Keep push trigger for master branch only
- Add workflow_dispatch to allow manual triggering on any branch when needed

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: justin808

.github/workflows/playwright.yml

@@ -1,9 +1,9 @@
 name: Playwright E2E Tests
 
 on:
-  pull_request:
   push:
     branches: [master]
+  workflow_dispatch:
 
 jobs:
   playwright: