Initial commit: Telegram Web Client with bot chat sync

- Backend: FastAPI + Telethon v2 WebSocket server
- Frontend: React + TypeScript + Vite + Zustand
- Features: Phone auth, 2FA, real-time bot chat
- Fix: Use chats= instead of from_users= to sync messages from all devices
- Config: BOT_USERNAME=AnvilForgeBot

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

telegram-web-client.service

@@ -0,0 +1,15 @@
+[Unit]
+Description=Telegram Web Client Backend
+After=network.target
+
+[Service]
+Type=simple
+User=root
+WorkingDirectory=/opt/telegram-web-client/backend
+Environment=PATH=/opt/telegram-web-client/backend/venv/bin:/usr/bin
+ExecStart=/opt/telegram-web-client/backend/venv/bin/uvicorn main:app --host 0.0.0.0 --port 8000
+Restart=always
+RestartSec=5
+
+[Install]
+WantedBy=multi-user.target