fix: revert investigative changes, keep root cause fixes only

Reverts diagnostic instrumentation and defensive hardening added during
memory leak investigation. Only root cause fixes survive.

Root causes fixed:
- SQLite driver: auto-finalize wrapper + PRAGMAs
- WS routers: delete clientConfigVersions on disconnect (unbounded Map leak)
- WS private router: same + Redis key cleanup

Reverted:
- Memory monitor, rate limiting, request timeouts (diagnostic/hardening)
- shutdownAuditLogger wiring, audit re-queue change, debug logs (cleanup/secondary)
- package-lock.json drift

server/routers/badger/exchangeSession.ts

@@ -41,7 +41,7 @@ export async function exchangeSession(
     res: Response,
     next: NextFunction
 ): Promise<any> {
-    logger.debug("Exchange session: Badger request received");
+    logger.debug("Exchange session: Badger sent", req.body);
 
     const parsedBody = exchangeSessionBodySchema.safeParse(req.body);