Database layer

…eation

Bug fix

#52, #53)

- Track all Firebase listeners via cleanup runnables in AndroidFirebase
- Add removeAllListeners() to FirebaseAPI interface
- Add stop() to GameNetworkHandler, called from GameScreen hide/dispose
- Fix confirmSetup: propagate errors to onError callback instead of
  silently calling onSuccess on failure paths
- Update SetupFlowController to pass error callback to confirmSetup

- Add CircuitBreaker class in new network package with three states:
  CLOSED (requests pass), OPEN (requests blocked), HALF_OPEN (one probe)
- Trips after 3 consecutive heartbeat failures, 10s cooldown before probe
- Integrate into GameNetworkHandler: gates saveMove and sendHeartbeat
- Connection UI reflects breaker state (Disconnected/Reconnecting/latency)

Route all database calls through state classes instead of calling
DatabaseManager directly from screen helpers.

- LobbyState: add validateLobby, listenForOpponentReady, startGame,
  listenForGameStart wrapper methods
- SetupState: add confirmSetup, unconfirmSetup, listenForBothSetupReady,
  getOpponentBoard, getFirebaseApi wrapper methods
- LobbyValidator: route through LobbyState instead of DatabaseManager
- LobbyFlowController: route through LobbyState
- SetupFlowController: route through SetupState
- GameNetworkHandler: accept FirebaseAPI via constructor injection
- Thread LobbyState through MainMenuScreen→MainMenuUI→JoinGamePanel
- Thread FirebaseAPI through SetupScreen→GameScreen→GameNetworkHandler

Result: zero DatabaseManager references in screens/ package

refactor: enforce GUI→Logic→Database layer separation

fix: add listener lifecycle management and confirmSetup error handling

feat: implement circuit breaker with closed/open/half-open states

The game now allows you to reconnect to a game, but if it takes more than 10 seconds the game is auto forfeited.
Both players latency is now displayed

Improve circuitbreak

…lobby-and-setup

Add heartbeat/circuitbreak to lobby and setup