ci: also run Test Stats Plugin workflow on fix/ci-type-errors-and-stale-test-date

main is now a dist-only orphan with no source code, so CI never fires on
it again. Add this source branch to the trigger list so that pushes and
PRs targeting fix/ci-type-errors-and-stale-test-date (e.g. PR #24) get
CI validation.

https://claude.ai/code/session_011jT6rDWtzsZphizRMFEp96

Author: erudenko

.github/workflows/test-stats.yml

@@ -2,12 +2,12 @@ name: Test Stats Plugin
 
 on:
   push:
-    branches: [main]
+    branches: [main, fix/ci-type-errors-and-stale-test-date]
     paths:
       - 'plugins/stats/**'
       - '.github/workflows/test-stats.yml'
   pull_request:
-    branches: [main]
+    branches: [main, fix/ci-type-errors-and-stale-test-date]
     paths:
       - 'plugins/stats/**'
       - '.github/workflows/test-stats.yml'