fix: auto-approve bot review when PR base is changed off main (#1971)

* fix: reset bot review when PR base is changed off main

The check-pr-target workflow only ran on 'opened' events targeting main,
so it never re-ran after a submitter edited the base branch to 'staged'.
The REQUEST_CHANGES review was left in place, blocking merge and requiring
a manual maintainer override.

Changes:
- Broaden trigger to also fire on edited, reopened, and synchronize events,
  and add 'staged' to the branches filter so the workflow runs after a
  base-branch edit.
- Before posting REQUEST_CHANGES, check whether the bot already has an
  active CHANGES_REQUESTED review to avoid duplicate reviews.
- After a base-branch edit: if the PR no longer targets main and the bot's
  latest review state is CHANGES_REQUESTED, post an APPROVE review to
  clear the block automatically.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* fix: rerun PR target check for any base branch

Co-authored-by: aaronpowell <434140+aaronpowell@users.noreply.github.com>

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: aaronpowell <434140+aaronpowell@users.noreply.github.com>

.github/workflows/check-pr-target.yml

@@ -2,8 +2,11 @@ name: Check PR Target Branch
 
 on:
   pull_request_target:
-    branches: [main]
+    types: [opened, edited, reopened, synchronize]
-    types: [opened]
+
+concurrency:
+  group: check-pr-target-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
 
 permissions:
   pull-requests: write
@@ -16,20 +19,62 @@ jobs:
         uses: actions/github-script@f28e40c7f34bde8b3046d885e986cb6290c5673b # v7.1.0
         with:
           script: |
-            const body = [
+            const pull = context.payload.pull_request;
-              '⚠️ **This PR targets `main`, but PRs should target `staged`.**',
+            const owner = context.repo.owner;
-              '',
+            const repo = context.repo.repo;
-              'The `main` branch is auto-published from `staged` and should not receive direct PRs.',
+            const pullNumber = context.issue.number;
-              'Please close this PR and re-open it against the `staged` branch.',
+            const botLogin = 'github-actions[bot]';
-              '',
-              'You can change the base branch using the **Edit** button at the top of this PR,',
-              'or run: `gh pr edit ${{ github.event.pull_request.number }} --base staged`'
-            ].join('\n');
 
-            await github.rest.pulls.createReview({
+            const { data: reviews } = await github.rest.pulls.listReviews({
-              owner: context.repo.owner,
+              owner,
-              repo: context.repo.repo,
+              repo,
-              pull_number: context.issue.number,
+              pull_number: pullNumber,
-              event: 'REQUEST_CHANGES',
+              per_page: 100
-              body
             });
+
+            const latestBotReview = reviews
+              .filter((review) => review.user?.login === botLogin)
+              .sort((a, b) => new Date(a.submitted_at ?? a.created_at) - new Date(b.submitted_at ?? b.created_at))
+              .at(-1);
+
+            const latestBotState = latestBotReview?.state;
+
+            if (pull.base.ref === 'main') {
+              if (latestBotState !== 'CHANGES_REQUESTED') {
+                const requestChangesBody = [
+                  '⚠️ **This PR targets `main`, but PRs should target `staged`.**',
+                  '',
+                  'The `main` branch is auto-published from `staged` and should not receive direct PRs.',
+                  'Please close this PR and re-open it against the `staged` branch.',
+                  '',
+                  'You can change the base branch using the **Edit** button at the top of this PR,',
+                  'or run: `gh pr edit ${{ github.event.pull_request.number }} --base staged`'
+                ].join('\n');
+
+                await github.rest.pulls.createReview({
+                  owner,
+                  repo,
+                  pull_number: pullNumber,
+                  event: 'REQUEST_CHANGES',
+                  body: requestChangesBody
+                });
+              }
+
+              return;
+            }
+
+            if (latestBotState === 'CHANGES_REQUESTED') {
+              const approveBody = [
+                '✅ Base branch is now set correctly.',
+                '',
+                'Removing the prior block because this PR no longer targets `main`.'
+              ].join('\n');
+
+              await github.rest.pulls.createReview({
+                owner,
+                repo,
+                pull_number: pullNumber,
+                event: 'APPROVE',
+                body: approveBody
+              });
+            }