fix(e2e): add missing @cfworker/json-schema dep to node-express-mcp-v2

@modelcontextprotocol/server declares it as an optional peer dependency,
so pnpm doesn't install it automatically. Without it the app fails at
startup with ERR_MODULE_NOT_FOUND.

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

Author: betegon

dev-packages/e2e-tests/test-applications/node-express-mcp-v2/package.json

@@ -11,6 +11,7 @@
     "test:assert": "pnpm test"
   },
   "dependencies": {
+    "@cfworker/json-schema": "^4.0.0",
     "@modelcontextprotocol/server": "2.0.0-alpha.2",
     "@modelcontextprotocol/node": "2.0.0-alpha.2",
     "@sentry/node": "latest || *",