Auto-create issue on Unity test failure

Mirrors pr-conflict-check.yml's pattern on the default branch so it's
active immediately instead of waiting for refactor-2026 to merge.

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

.github/workflows/tests.yml

@@ -6,6 +6,10 @@ on:
   pull_request:
     branches: [main]
 
+permissions:
+  contents: read
+  issues: write
+
 jobs:
   test:
     name: Run Unity Tests
@@ -39,3 +43,60 @@ jobs:
         with:
           name: test-results
           path: test-results/
+
+  report-failure:
+    name: Open issue on test failure
+    needs: test
+    if: failure()
+    runs-on: ubuntu-latest
+    steps:
+      - name: Create or update tracking issue
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const runUrl = `${context.serverUrl}/${context.repo.owner}/${context.repo.repo}/actions/runs/${context.runId}`;
+            const isPR = context.eventName === 'pull_request';
+
+            const subject = isPR
+              ? `PR #${context.payload.pull_request.number} ("${context.payload.pull_request.title}")`
+              : `commit ${context.sha.substring(0, 7)} on \`${context.ref.replace('refs/heads/', '')}\``;
+
+            const title = isPR
+              ? `Unity tests failing: PR #${context.payload.pull_request.number}`
+              : `Unity tests failing on ${context.ref.replace('refs/heads/', '')}`;
+
+            const body = [
+              `The **Automated Tests** workflow failed for ${subject}.`,
+              '',
+              `**Workflow run**: ${runUrl}`,
+              '',
+              'Check the Edit Mode / Play Mode test results artifact attached to the run',
+              'above for the specific failing test(s). This issue will stay open until a',
+              'follow-up run passes — close it manually once resolved.',
+            ].join('\n');
+
+            const { data: existing } = await github.rest.issues.listForRepo({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              state: 'open',
+              labels: 'ci-failure',
+            });
+
+            const match = existing.find(issue => issue.title === title);
+
+            if (match) {
+              await github.rest.issues.createComment({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: match.number,
+                body: `Still failing as of ${runUrl}.`,
+              });
+            } else {
+              await github.rest.issues.create({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                title,
+                body,
+                labels: ['ci-failure'],
+              });
+            }