feat: add periodic game.status broadcast and live status REST endpoint

Add 20-second game.status WebSocket heartbeat from active shard monitors
containing full game state, and GET /status-live REST endpoint for on-demand
polling. Fix missing token destructuring in SessionInfo causing crash.
Relax frontend polling from 3s to 60s since WebSocket events now cover
real-time updates. Bump version to 0.6.0.

Made-with: Cursor

tests/api/ecast-shard-client.test.js

@@ -376,8 +376,121 @@ describe('EcastShardClient', () => {
     });
   });
 
+  describe('getSnapshot', () => {
+    test('returns correct shape with current state', () => {
+      const client = new EcastShardClient({
+        sessionId: 1, gameId: 5, roomCode: 'LSBN', maxPlayers: 8, onEvent: () => {}
+      });
+      client.appTag = 'drawful2international';
+      client.playerCount = 3;
+      client.playerNames = ['Alice', 'Bob', 'Charlie'];
+      client.lobbyState = 'CanStart';
+      client.gameState = 'Lobby';
+      client.gameStarted = false;
+      client.gameFinished = false;
+
+      const snapshot = client.getSnapshot();
+
+      expect(snapshot).toEqual({
+        sessionId: 1,
+        gameId: 5,
+        roomCode: 'LSBN',
+        appTag: 'drawful2international',
+        maxPlayers: 8,
+        playerCount: 3,
+        players: ['Alice', 'Bob', 'Charlie'],
+        lobbyState: 'CanStart',
+        gameState: 'Lobby',
+        gameStarted: false,
+        gameFinished: false,
+        monitoring: true,
+      });
+    });
+
+    test('returns a defensive copy of playerNames', () => {
+      const client = new EcastShardClient({
+        sessionId: 1, gameId: 5, roomCode: 'TEST', maxPlayers: 8, onEvent: () => {}
+      });
+      client.playerNames = ['Alice'];
+
+      const snapshot = client.getSnapshot();
+      snapshot.players.push('Mutated');
+
+      expect(client.playerNames).toEqual(['Alice']);
+    });
+  });
+
+  describe('startStatusBroadcast / stopStatusBroadcast', () => {
+    beforeEach(() => jest.useFakeTimers());
+    afterEach(() => jest.useRealTimers());
+
+    test('broadcasts game.status every 20 seconds', () => {
+      const events = [];
+      const client = new EcastShardClient({
+        sessionId: 1, gameId: 5, roomCode: 'TEST', maxPlayers: 8,
+        onEvent: (type, data) => events.push({ type, data }),
+      });
+      client.playerCount = 2;
+      client.playerNames = ['A', 'B'];
+      client.gameState = 'Lobby';
+
+      client.startStatusBroadcast();
+
+      jest.advanceTimersByTime(20000);
+      expect(events).toHaveLength(1);
+      expect(events[0].type).toBe('game.status');
+      expect(events[0].data.monitoring).toBe(true);
+
+      jest.advanceTimersByTime(20000);
+      expect(events).toHaveLength(2);
+
+      client.stopStatusBroadcast();
+
+      jest.advanceTimersByTime(40000);
+      expect(events).toHaveLength(2);
+    });
+
+    test('disconnect stops the status broadcast', () => {
+      const events = [];
+      const client = new EcastShardClient({
+        sessionId: 1, gameId: 5, roomCode: 'TEST', maxPlayers: 8,
+        onEvent: (type, data) => events.push({ type, data }),
+      });
+
+      client.startStatusBroadcast();
+
+      jest.advanceTimersByTime(20000);
+      expect(events).toHaveLength(1);
+
+      client.disconnect();
+
+      jest.advanceTimersByTime(40000);
+      expect(events).toHaveLength(1);
+    });
+
+    test('handleWelcome starts status broadcast', () => {
+      const events = [];
+      const client = new EcastShardClient({
+        sessionId: 1, gameId: 5, roomCode: 'TEST', maxPlayers: 8,
+        onEvent: (type, data) => events.push({ type, data }),
+      });
+
+      client.handleWelcome({
+        id: 7,
+        secret: 'abc',
+        reconnect: false,
+        entities: {},
+        here: {},
+      });
+
+      jest.advanceTimersByTime(20000);
+      const statusEvents = events.filter(e => e.type === 'game.status');
+      expect(statusEvents).toHaveLength(1);
+    });
+  });
+
   describe('module exports', () => {
-    const { startMonitor, stopMonitor, cleanupAllShards } = require('../../backend/utils/ecast-shard-client');
+    const { startMonitor, stopMonitor, cleanupAllShards, getMonitorSnapshot } = require('../../backend/utils/ecast-shard-client');
 
     test('startMonitor is exported', () => {
       expect(typeof startMonitor).toBe('function');
@@ -390,6 +503,15 @@ describe('EcastShardClient', () => {
     test('cleanupAllShards is exported', () => {
       expect(typeof cleanupAllShards).toBe('function');
     });
+
+    test('getMonitorSnapshot is exported', () => {
+      expect(typeof getMonitorSnapshot).toBe('function');
+    });
+
+    test('getMonitorSnapshot returns null when no shard active', () => {
+      const snapshot = getMonitorSnapshot(999, 999);
+      expect(snapshot).toBeNull();
+    });
   });
 
   describe('handleError with code 2027', () => {