Add workflow_dispatch trigger to Node.js CI

Allows manual workflow runs for testing and debugging.

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

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

Author: guimard

.github/workflows/buildandtest.yml

@@ -8,6 +8,7 @@ on:
     branches: [master]
   pull_request:
     branches: [master]
+  workflow_dispatch:
 
 jobs:
   build: