chore(mcp): add cors to oauth metadata route

Author: stainless-app[bot]

packages/mcp-server/package.json

@@ -30,6 +30,7 @@
     "isaacus": "file:../../dist/",
     "@cloudflare/cabidela": "^0.2.4",
     "@modelcontextprotocol/sdk": "^1.11.5",
+    "cors": "^2.8.5",
     "express": "^5.1.0",
     "jq-web": "https://github.com/stainless-api/jq-web/releases/download/v0.8.6/jq-web.tar.gz",
     "qs": "^6.14.0",
@@ -42,6 +43,7 @@
     "mcp-server": "dist/index.js"
   },
   "devDependencies": {
+    "@types/cors": "^2.8.19",
     "@types/express": "^5.0.3",
     "@types/jest": "^29.4.0",
     "@types/yargs": "^17.0.8",