Trigger CI on draft-to-ready PR conversion

Add ready_for_review to pull_request activity types so self-hosted
tests run automatically when a PR is converted from draft to ready.
Previously this required an empty commit or force-push to re-trigger.

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

Author: sbryngelson

.github/workflows/test.yml

@@ -4,6 +4,7 @@ on:
   push:
     branches: [master]
   pull_request:
+    types: [opened, synchronize, reopened, ready_for_review]
   workflow_dispatch:
 
 concurrency: