add metrics middleware to ogcard service

bskyogcard/package.json

@@ -14,13 +14,16 @@
     "@atproto/common": "^0.4.0",
     "@resvg/resvg-js": "^2.6.2",
     "express": "^4.19.2",
+    "express-prom-bundle": "^7.0.0",
     "http-terminator": "^3.2.0",
     "pino": "^9.2.0",
+    "prom-client": "^15.1.3",
     "react": "^18.3.1",
     "satori": "^0.10.13",
     "twemoji": "^14.0.2"
   },
   "devDependencies": {
+    "@types/express": "^4.17.21",
     "@types/node": "^20.14.3",
     "ts-node": "^10.9.2",
     "typescript": "^5.4.5"