fix: resolve socket-server import path for Next.js build

Create a wrapper module in src/lib/socket-io.ts that provides access
to the socket.io server instance for API routes, avoiding the build
error caused by importing from outside the src directory.

The wrapper uses dynamic imports to lazy-load the socket server module
only on the server-side, making it safe for Next.js to bundle.

Changes:
- Add src/lib/socket-io.ts with async getSocketIO() function
- Update join route to use @/lib/socket-io import
- Update leave route to use @/lib/socket-io import
- Both routes now await getSocketIO() since it's async

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

apps/web/src/app/api/arcade/rooms/[roomId]/join/route.ts

@@ -3,7 +3,7 @@ import { getRoomById, touchRoom } from '@/lib/arcade/room-manager'
 import { addRoomMember, getOnlineRoomMembers } from '@/lib/arcade/room-membership'
 import { getActivePlayers, getRoomActivePlayers } from '@/lib/arcade/player-manager'
 import { getViewerId } from '@/lib/viewer'
-import { getSocketIO } from '../../../../../../socket-server'
+import { getSocketIO } from '@/lib/socket-io'
 
 type RouteContext = {
   params: Promise<{ roomId: string }>
@@ -58,7 +58,7 @@ export async function POST(req: NextRequest, context: RouteContext) {
     await touchRoom(roomId)
 
     // Broadcast to all users in the room via socket
-    const io = getSocketIO()
+    const io = await getSocketIO()
     if (io) {
       try {
         const onlineMembers = await getOnlineRoomMembers(roomId)

apps/web/src/app/api/arcade/rooms/[roomId]/leave/route.ts

@@ -3,7 +3,7 @@ import { getRoomById } from '@/lib/arcade/room-manager'
 import { getOnlineRoomMembers, isMember, removeMember } from '@/lib/arcade/room-membership'
 import { getRoomActivePlayers } from '@/lib/arcade/player-manager'
 import { getViewerId } from '@/lib/viewer'
-import { getSocketIO } from '../../../../../../socket-server'
+import { getSocketIO } from '@/lib/socket-io'
 
 type RouteContext = {
   params: Promise<{ roomId: string }>
@@ -34,7 +34,7 @@ export async function POST(_req: NextRequest, context: RouteContext) {
     await removeMember(roomId, viewerId)
 
     // Broadcast to all remaining users in the room via socket
-    const io = getSocketIO()
+    const io = await getSocketIO()
     if (io) {
       try {
         const onlineMembers = await getOnlineRoomMembers(roomId)

apps/web/src/lib/socket-io.ts

@@ -0,0 +1,39 @@
+/**
+ * Socket.IO server instance accessor for API routes
+ * This module provides a way for API routes to access the socket.io server
+ * to broadcast real-time updates.
+ */
+
+import type { Server as SocketIOServerType } from 'socket.io'
+
+// Import the socket server module (this is safe because it's only used in Node.js context)
+let socketServer: { getSocketIO: () => SocketIOServerType | null } | null = null
+
+// Lazy-load the socket server module (only works on server-side)
+async function loadSocketServer() {
+  if (typeof window !== 'undefined') {
+    // Client-side: return null
+    return null
+  }
+
+  if (!socketServer) {
+    try {
+      // Dynamic import to avoid bundling issues
+      socketServer = await import('../../socket-server')
+    } catch (error) {
+      console.error('[Socket IO] Failed to load socket server:', error)
+      return null
+    }
+  }
+
+  return socketServer
+}
+
+/**
+ * Get the socket.io server instance
+ * Returns null if not initialized or if called on client-side
+ */
+export async function getSocketIO(): Promise<SocketIOServerType | null> {
+  const server = await loadSocketServer()
+  return server ? server.getSocketIO() : null
+}