feat(phase6): Add sounds, team chat, reactions, monitor, settings, and CSV import/export

Sound System:
- Add soundStore with volume/mute persistence
- Add useSound hook with Web Audio API fallback
- Add SoundControl component for in-game volume adjustment
- Play sounds for correct/incorrect, steal, timer, victory/defeat

Team Chat:
- Add TeamChat component with collapsible panel
- Add team_message WebSocket event (team-only visibility)
- Store up to 50 messages per session

Emoji Reactions:
- Add EmojiReactions bar with 8 emojis
- Add ReactionOverlay with floating animations (Framer Motion)
- Add rate limiting (1 reaction per 3 seconds)
- Broadcast reactions to all players in room

Admin Monitor:
- Add Monitor page showing active rooms from Redis
- Display player counts, team composition, status
- Add ability to close problematic rooms

Admin Settings:
- Add Settings page for game configuration
- Configure points/times by difficulty, steal penalty, max players
- Store config in JSON file with service helpers

CSV Import/Export:
- Add export endpoint with optional filters
- Add import endpoint with validation and error reporting
- Add UI buttons and import result modal in Questions page

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/src/components/chat/EmojiReactions.tsx

@@ -0,0 +1,89 @@
+import { useState, useCallback, useEffect } from 'react'
+import { motion } from 'framer-motion'
+import { useSocket } from '../../hooks/useSocket'
+import { useGameStore } from '../../stores/gameStore'
+import { useThemeStyles } from '../../themes/ThemeProvider'
+
+const EMOJIS = ['👏', '😮', '😂', '🔥', '💀', '🎉', '😭', '🤔']
+const COOLDOWN_MS = 3000 // 3 seconds cooldown
+
+export default function EmojiReactions() {
+  const { sendReaction } = useSocket()
+  const { room, playerName } = useGameStore()
+  const { config } = useThemeStyles()
+  const [isDisabled, setIsDisabled] = useState(false)
+  const [cooldownRemaining, setCooldownRemaining] = useState(0)
+
+  // Handle cooldown timer display
+  useEffect(() => {
+    if (!isDisabled) return
+
+    const interval = setInterval(() => {
+      setCooldownRemaining((prev) => {
+        if (prev <= 100) {
+          setIsDisabled(false)
+          return 0
+        }
+        return prev - 100
+      })
+    }, 100)
+
+    return () => clearInterval(interval)
+  }, [isDisabled])
+
+  const handleEmojiClick = useCallback(
+    (emoji: string) => {
+      if (isDisabled || !room?.code) return
+
+      // Send the reaction via socket
+      sendReaction(emoji, room.code, playerName)
+
+      // Enable cooldown
+      setIsDisabled(true)
+      setCooldownRemaining(COOLDOWN_MS)
+    },
+    [isDisabled, room?.code, playerName, sendReaction]
+  )
+
+  if (!room) return null
+
+  return (
+    <motion.div
+      initial={{ opacity: 0, y: 20 }}
+      animate={{ opacity: 1, y: 0 }}
+      className="flex items-center gap-2 px-4 py-2 rounded-full"
+      style={{
+        backgroundColor: `${config.colors.bg}CC`,
+        backdropFilter: 'blur(8px)',
+        border: `1px solid ${config.colors.primary}40`,
+      }}
+    >
+      {EMOJIS.map((emoji) => (
+        <motion.button
+          key={emoji}
+          onClick={() => handleEmojiClick(emoji)}
+          disabled={isDisabled}
+          whileHover={!isDisabled ? { scale: 1.2 } : {}}
+          whileTap={!isDisabled ? { scale: 0.9 } : {}}
+          className={`text-2xl p-2 rounded-lg transition-all ${
+            isDisabled ? 'opacity-40 cursor-not-allowed grayscale' : 'cursor-pointer hover:bg-white/10'
+          }`}
+          title={isDisabled ? `Espera ${Math.ceil(cooldownRemaining / 1000)}s` : emoji}
+        >
+          {emoji}
+        </motion.button>
+      ))}
+
+      {/* Cooldown indicator */}
+      {isDisabled && (
+        <motion.div
+          initial={{ width: '100%' }}
+          animate={{ width: '0%' }}
+          transition={{ duration: COOLDOWN_MS / 1000, ease: 'linear' }}
+          className="absolute bottom-0 left-0 h-1 rounded-full"
+          style={{ backgroundColor: config.colors.primary }}
+        />
+      )}
+    </motion.div>
+  )
+}