fix(memory): use bodyStore to avoid closure capturing request body

Problem:
- Stream response handlers (res.on) captured requestOptions in closures
- requestOptions contained originalBodyString (~800KB per request)
- These strings couldn't be GC'd until stream completed
- With concurrent requests, memory accumulated rapidly

Solution:
- Store request body strings in this.bodyStore Map with unique ID
- Pass only bodyStoreId in requestOptions (not the 800KB string)
- Closures capture small ID, not large string
- Clean up bodyStore on request completion (success/error/timeout)
- Extract needed values before closures to avoid capturing body object

package.json

@@ -59,6 +59,7 @@
     "dotenv": "^16.3.1",
     "express": "^4.18.2",
     "google-auth-library": "^10.1.0",
+    "heapdump": "^0.3.15",
     "helmet": "^7.1.0",
     "https-proxy-agent": "^7.0.2",
     "inquirer": "^8.2.6",