fix: ghost players on back - leaveRoom, store.reset, dynamic lobby slots

server/src/index.js

@@ -119,6 +119,19 @@ io.on('connection', (socket) => {
     }
   })
 
+  // ─── Quitter une salle explicitement (bouton retour) ────────────────────────
+  socket.on('leave-room', ({ roomId }) => {
+    const room = rooms.get(roomId)
+    if (room) {
+      room.removePlayer(socket.id)
+      socket.leave(roomId)
+      io.to(roomId).emit('room-update', { players: room.getPlayersInfo() })
+      if (room.playerCount === 0) rooms.delete(roomId)
+      console.log(`[${roomId}] ${socket.data.playerName ?? socket.id} a quitté`)
+    }
+    socket.data.roomId = null
+  })
+
   // ─── Déconnexion ─────────────────────────────────────────────────────────────
   socket.on('disconnect', () => {
     const roomId = socket.data.roomId