Story 26: Establish TDD workflow and quality gates

Add workflow engine with acceptance gates, test recording, and review
queue. Frontend displays gate status (blocked/ready), test summaries,
failing badges, and warnings. Proceed action is disabled when gates
are not met. Includes 13 unit tests (Vitest) and 9 E2E tests
(Playwright) covering all five acceptance criteria.

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

frontend/tsconfig.node.json

@@ -4,7 +4,8 @@
     "skipLibCheck": true,
     "module": "ESNext",
     "moduleResolution": "bundler",
-    "allowSyntheticDefaultImports": true
+    "allowSyntheticDefaultImports": true,
+    "types": ["node"]
   },
-  "include": ["vite.config.ts"]
+  "include": ["vite.config.ts", "playwright.config.ts"]
 }