docs(bd-2x9): note that WorkerGrid E2E test already exists

The test file at src/tui/components/WorkerGrid.e2e.test.ts already
exists and passes all 13 tests covering status color rendering.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

notes/bd-2x9.md

@@ -0,0 +1,21 @@
+# Bead bd-2x9: WorkerGrid E2E Test
+
+## Task
+Create an E2E test that verifies WorkerGrid component renders worker entries with correct status colors (green for active, yellow for idle, red for error).
+
+## Outcome
+The test file already existed at `src/tui/components/WorkerGrid.e2e.test.ts` and passes all 13 tests.
+
+## Test Coverage
+The existing test covers:
+- Status color rendering (green for active, yellow for idle, red for error)
+- Status icons with colors (●, ○, ✗)
+- Worker entry formatting
+- Color consistency across status updates
+- Complete realistic workflow scenario
+
+## Verification
+```bash
+npm test -- src/tui/components/WorkerGrid.e2e.test.ts
+# ✓ 13 tests passed in 6ms
+```