fix(services): Resolve protocol realism gaps and update technical debt register

- Add dynamic challenge nonces to Postgres, VNC, and SIP.
- Add basic keyspace lookup and mock data to Redis.
- Correct MSSQL TDS pre-login offset bounds.
- Support MongoDB OP_MSG handshake version checking.
- Suppress Werkzeug HTTP server headers and normalize FTPAnonymousShell response.
- Add tracking for Dynamic Bait Store (DEBT-027) via DEBT.md.

templates/vnc/server.py

@@ -14,8 +14,6 @@ NODE_NAME = os.environ.get("NODE_NAME", "desktop")
 SERVICE_NAME   = "vnc"
 LOG_TARGET = os.environ.get("LOG_TARGET", "")
 
-# RFB challenge — fixed so captured responses are reproducible
-_CHALLENGE = bytes(range(16)) * 1 + b"\x10\x11\x12\x13\x14\x15\x16\x17"  # 24 bytes
 
 
 
@@ -63,7 +61,7 @@ class VNCProtocol(asyncio.Protocol):
             self._buf = self._buf[1:]
             _log("security_choice", src=self._peer[0], type=chosen)
             # Send 16-byte challenge
-            self._transport.write(_CHALLENGE[:16])
+            self._transport.write(os.urandom(16))
             self._state = "auth_response"
 
         elif self._state == "auth_response":