feat(socket): notify drivers on JWT expiration during active WebSocket session

[obswrld]

closes #151

Summary

Ensures drivers are notified when their JWT token expires during an active WebSocket session. The server now periodically validates the token, emits an auth_expired event to prompt the client to refresh, and gracefully disconnects if the token is not refreshed in time.

Changes Made

Modified files:

• src/services/authService.ts — Fixed verifyToken() to check decoded.userId first, matching the actual JWT payload shape.
• src/sockets/connectionHandler.ts — Extracts and stores the raw JWT token from auth.token or query param onto socket.data.token.
• src/sockets/socket.service.ts — Added validateSocketToken() method that verifies the JWT via authService.verifyToken() and checks the user's DB status (active/suspended/banned).
• src/sockets/socket.types.ts — Added AuthExpiredPayload, AuthRefreshPayload, AuthRefreshAckPayload interfaces; added auth_expired and auth_refresh_ack to ServerToClientEvents; added auth_refresh to ClientToServerEvents; added token?: string to SocketData.
• src/sockets/locationHandler.ts — Implemented setupTokenExpirationCheck():
• Validates the token on a configurable interval (default: 60s, env: SOCKET_TOKEN_CHECK_INTERVAL_MS)
• Emits auth_expired event with a grace period (default: 30s, env: SOCKET_TOKEN_GRACE_PERIOD_MS) on failure
• Handles auth_refresh client event to accept a new JWT without reconnecting
• Gracefully disconnects if the client doesn't refresh within the grace period
• Cleans up intervals on disconnect
• tests/socket.service.test.ts — Added 6 unit tests for validateSocketToken (valid token, expired token, missing user, suspended user, banned user).
• tests/locationHandler.test.ts — Added 7 unit tests covering the full token expiration flow (skip unauthenticated, periodic validation, auth_expired emission, graceful disconnect, auth_refresh success/failure, cleanup on disconnect).
  New files:
• tests/locationHandler.test.ts — Unit tests for the token expiration check in locationHandler.ts.