fix: remove unused heapdump dependency

The heapdump package was added in v1.1.257 but is not actually used anywhere in the codebase.

This causes build failures on platforms without Python (e.g., Zeabur) because heapdump requires node-gyp compilation.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

package.json

@@ -59,7 +59,6 @@
     "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",