feat: add Discord bot integration

- Discord bot runs in background thread alongside desktop app
- State synchronization between Discord and desktop waifu
- Commands: !hello, !status
- Responds to mentions and DMs
- Complete setup guide in DISCORD_SETUP.md
- Graceful fallback if no token configured

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

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

main.py

@@ -4,6 +4,7 @@ A VRM-based AI desktop companion with Discord integration
 """
 import sys
 import asyncio
+import threading
 from PyQt6.QtWidgets import QApplication
 from PyQt6.QtCore import Qt
 from dotenv import load_dotenv
@@ -16,6 +17,31 @@ from src.ui.waifu_window import WaifuWindow
 from src.discord_bot.bot import WaifuBot
 from src.core.state_manager import StateManager
 
+def run_discord_bot(state_manager: StateManager):
+    """Run Discord bot in a separate thread"""
+    import os
+    token = os.getenv('DISCORD_BOT_TOKEN')
+    if not token:
+        print("Discord bot disabled: DISCORD_BOT_TOKEN not set in .env file")
+        return
+
+    # Create new event loop for this thread
+    loop = asyncio.new_event_loop()
+    asyncio.set_event_loop(loop)
+
+    # Create and start bot
+    bot = WaifuBot(state_manager)
+    try:
+        print("Starting Discord bot...")
+        loop.run_until_complete(bot.start(token))
+    except KeyboardInterrupt:
+        print("Discord bot shutting down...")
+        loop.run_until_complete(bot.close())
+    except Exception as e:
+        print(f"Discord bot error: {e}")
+    finally:
+        loop.close()
+
 def main():
     """Main application entry point"""
     # Create Qt Application
@@ -29,10 +55,9 @@ def main():
     window = WaifuWindow(state_manager)
     window.show()
 
-    # Start Discord bot in background (if configured)
-    # TODO: Implement Discord bot integration
-    # discord_bot = WaifuBot(state_manager)
-    # asyncio.create_task(discord_bot.start())
+    # Start Discord bot in background thread
+    discord_thread = threading.Thread(target=run_discord_bot, args=(state_manager,), daemon=True)
+    discord_thread.start()
 
     # Run application
     sys.exit(app.exec())