fix: remove duplicate ModerationNotifications causing double toasts

**Root Cause:**
- ModerationNotifications was rendered in BOTH /arcade/room/page.tsx AND PageWithNav
- Both had separate useRoomData hooks, creating two socket listeners
- When join-request-submitted event fired, BOTH instances showed a toast
- Clicking "Approve" only closed one toast, leaving the other visible

**Fix:**
- Removed ModerationNotifications from room page entirely
- PageWithNav (inside MemoryPairsGame) already handles all moderation events
- Now only ONE instance listens and renders, so approvals properly dismiss

**Files Changed:**
- Removed ModerationNotifications import from room page
- Removed all 4 instances of <ModerationNotifications /> from room page
- Removed moderationEvent and clearModerationEvent from useRoomData destructuring
- Added comment explaining PageWithNav handles notifications

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

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

apps/web/src/app/arcade/room/page.tsx

@@ -1,7 +1,6 @@
 'use client'
 
 import { useRoomData } from '@/hooks/useRoomData'
-import { ModerationNotifications } from '@/components/nav/ModerationNotifications'
 import { MemoryPairsGame } from '../matching/components/MemoryPairsGame'
 import { RoomMemoryPairsProvider } from '../matching/context/RoomMemoryPairsProvider'
 
@@ -11,60 +10,57 @@ import { RoomMemoryPairsProvider } from '../matching/context/RoomMemoryPairsProv
  *
  * Note: We don't redirect to /arcade if no room exists to avoid navigation loops.
  * Instead, we show a friendly message with a link back to the Champion Arena.
+ *
+ * Note: ModerationNotifications is handled by PageWithNav inside each game component,
+ * so we don't need to render it here.
  */
 export default function RoomPage() {
-  const { roomData, isLoading, moderationEvent, clearModerationEvent } = useRoomData()
+  const { roomData, isLoading } = useRoomData()
 
   // Show loading state
   if (isLoading) {
     return (
-      <>
-        <div
-          style={{
-            display: 'flex',
-            alignItems: 'center',
-            justifyContent: 'center',
-            height: '100vh',
-            fontSize: '18px',
-            color: '#666',
-          }}
-        >
-          Loading room...
-        </div>
-        <ModerationNotifications moderationEvent={moderationEvent} onClose={clearModerationEvent} />
-      </>
+      <div
+        style={{
+          display: 'flex',
+          alignItems: 'center',
+          justifyContent: 'center',
+          height: '100vh',
+          fontSize: '18px',
+          color: '#666',
+        }}
+      >
+        Loading room...
+      </div>
     )
   }
 
   // Show error if no room (instead of redirecting)
   if (!roomData) {
     return (
-      <>
-        <div
+      <div
+        style={{
+          display: 'flex',
+          flexDirection: 'column',
+          alignItems: 'center',
+          justifyContent: 'center',
+          height: '100vh',
+          fontSize: '18px',
+          color: '#666',
+          gap: '1rem',
+        }}
+      >
+        <div>No active room found</div>
+        <a
+          href="/arcade"
           style={{
-            display: 'flex',
-            flexDirection: 'column',
-            alignItems: 'center',
-            justifyContent: 'center',
-            height: '100vh',
-            fontSize: '18px',
-            color: '#666',
-            gap: '1rem',
+            color: '#3b82f6',
+            textDecoration: 'underline',
           }}
         >
-          <div>No active room found</div>
-          <a
-            href="/arcade"
-            style={{
-              color: '#3b82f6',
-              textDecoration: 'underline',
-            }}
-          >
-            Go to Champion Arena
-          </a>
-        </div>
-        <ModerationNotifications moderationEvent={moderationEvent} onClose={clearModerationEvent} />
-      </>
+          Go to Champion Arena
+        </a>
+      </div>
     )
   }
 
@@ -72,38 +68,26 @@ export default function RoomPage() {
   switch (roomData.gameName) {
     case 'matching':
       return (
-        <>
-          <RoomMemoryPairsProvider>
-            <MemoryPairsGame />
-          </RoomMemoryPairsProvider>
-          <ModerationNotifications
-            moderationEvent={moderationEvent}
-            onClose={clearModerationEvent}
-          />
-        </>
+        <RoomMemoryPairsProvider>
+          <MemoryPairsGame />
+        </RoomMemoryPairsProvider>
       )
 
     // TODO: Add other games (complement-race, memory-quiz, etc.)
     default:
       return (
-        <>
-          <div
-            style={{
-              display: 'flex',
-              alignItems: 'center',
-              justifyContent: 'center',
-              height: '100vh',
-              fontSize: '18px',
-              color: '#666',
-            }}
-          >
-            Game "{roomData.gameName}" not yet supported
-          </div>
-          <ModerationNotifications
-            moderationEvent={moderationEvent}
-            onClose={clearModerationEvent}
-          />
-        </>
+        <div
+          style={{
+            display: 'flex',
+            alignItems: 'center',
+            justifyContent: 'center',
+            height: '100vh',
+            fontSize: '18px',
+            color: '#666',
+          }}
+        >
+          Game "{roomData.gameName}" not yet supported
+        </div>
       )
   }
 }