fix: make useArcadeSocket work without ArcadeErrorProvider

CRITICAL PRODUCTION FIX - Resolves runtime error breaking all arcade games.

**Problem:**
- Commit 59901c55 added useArcadeError() call to useArcadeSocket
- Pages not wrapped with ArcadeErrorProvider yet
- Runtime error: "useArcadeError must be used within ArcadeErrorProvider"
- Next.js error boundary shows generic error page with no navigation or recovery

**Solution:**
- Export ArcadeErrorContext from ArcadeErrorContext.tsx
- Use useContext directly in useArcadeSocket instead of useArcadeError hook
- Fall back to no-op function if provider not available
- Allows games to work without error provider (just won't show error toasts)
- Pages can be wrapped with provider incrementally in future commits

**Impact:**
- Fixes production runtime error immediately
- Games work normally (without error toasts)
- Error provider can be added to pages when ready

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

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

apps/web/src/contexts/ArcadeErrorContext.tsx

@@ -7,7 +7,7 @@ interface ArcadeErrorContextValue {
   addError: (message: string, details?: string) => void
 }
 
-const ArcadeErrorContext = createContext<ArcadeErrorContextValue | null>(null)
+export const ArcadeErrorContext = createContext<ArcadeErrorContextValue | null>(null)
 
 /**
  * Provider for arcade error management

apps/web/src/hooks/useArcadeSocket.ts

@@ -1,7 +1,7 @@
-import { useCallback, useEffect, useRef, useState } from 'react'
+import { useCallback, useEffect, useRef, useState, useContext } from 'react'
 import { io, type Socket } from 'socket.io-client'
 import type { GameMove } from '@/lib/arcade/validation'
-import { useArcadeError } from '@/contexts/ArcadeErrorContext'
+import { ArcadeErrorContext } from '@/contexts/ArcadeErrorContext'
 
 export interface ArcadeSocketEvents {
   onSessionState?: (data: {
@@ -39,7 +39,10 @@ export function useArcadeSocket(events: ArcadeSocketEvents = {}): UseArcadeSocke
   const [socket, setSocket] = useState<Socket | null>(null)
   const [connected, setConnected] = useState(false)
   const eventsRef = useRef(events)
-  const { addError } = useArcadeError()
+
+  // Get error context if available, but don't throw if it's not
+  const errorContext = useContext(ArcadeErrorContext)
+  const addError = errorContext?.addError || (() => {})
 
   // Update events ref when they change
   useEffect(() => {