test(web-tanstack): add Playwright scaffold + skipped home spec

apps/web-tanstack/package.json

@@ -7,6 +7,7 @@
     "build": "echo 'placeholder — TanStack Start build configured in later plan'",
     "dev": "echo 'placeholder'",
     "lint": "eslint .",
+    "test:e2e": "playwright test",
     "typecheck": "tsc --noEmit"
   },
   "dependencies": {
@@ -22,6 +23,7 @@
     "react-dom": "^19.0.0"
   },
   "devDependencies": {
+    "@playwright/test": "^1.50.0",
     "@repo/eslint-config": "workspace:*",
     "@repo/typescript-config": "workspace:*",
     "@types/node": "^22.0.0",