fix(ci): trigger AI review on follow-up commits to PR

- Add `synchronize` event to trigger on new commits pushed to PR
- Add `reopened` event to trigger when PR is reopened
- Update documentation comments to reflect new behavior
- Keep cancel-in-progress to prevent stale reviews

Fixes issue where AI review only ran on PR creation, requiring
manual /review comment for subsequent commits.

.github/workflows/ai-review.yml

@@ -3,15 +3,18 @@
 # Posts as ccs-agy-reviewer[bot] via GitHub App
 #
 # Triggers:
-# - Automatically when PR is first opened
+# - Automatically when PR is opened, receives new commits, or is reopened
 # - Manually via /review comment on PR
 # - Manually via workflow_dispatch
+#
+# Note: Concurrency group cancels in-progress reviews when new commits arrive.
+# This prevents wasting resources on outdated code reviews.
 
 name: AI Code Review
 
 on:
   pull_request_target:
-    types: [opened]  # Only on first open, not synchronize (avoids cancel-on-push)
+    types: [opened, synchronize, reopened]
   issue_comment:
     types: [created]
   workflow_dispatch:
@@ -38,7 +41,7 @@ jobs:
       id-token: write
 
     # Conditions:
-    # - PR event: only on opened (not synchronize to avoid cancel-on-push)
+    # - PR event: on opened, synchronize (new commits), or reopened
     # - Comment event: only if it's a PR, contains /review, and NOT from a bot
     if: >
       github.event_name == 'pull_request_target' ||