refactor: move auth and websocket handlers out of lib.rs, clean up main.rs

lib.rs is doing too much. It currently owns:
- The `verify_token` auth helper (lines 32-61)
- The` ws_handler` websocket upgrade handler (lines 63-83)
- The `peroxo`_route router constructor (lines 85-92)
- Proto includes and all module declarations

`main.rs` has a commented-out MongoDb config line (line 16) and a commented-out builder call (line 21) left over from an earlier iteration.

Start by reading lib.rs at the verify_token, ws_handler, and peroxo_route sections, then inspect main.rs lines 16 and 21 and the existing module and proto declarations. Organize these responsibilities outside lib.rs, remove the obsolete commented MongoDB and builder lines, and verify that the application structure and behavior remain intact.

Written by the indexing model from the issue text.