feat: Allow manual workflow triggering

Add workflow_dispatch trigger to enable manual test runs from GitHub Actions UI.

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

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

Author: GhostTypes

.github/workflows/test.yml

@@ -25,6 +25,7 @@ on:
       - 'tsconfig.json'
       - 'vitest.config.ts'
       - '.github/workflows/test.yml'
+  workflow_dispatch:
 
 jobs:
   test: