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>

backend/config.py

@@ -0,0 +1,18 @@
+import os
+from dotenv import load_dotenv
+
+load_dotenv()
+
+# Telegram API credentials (get from https://my.telegram.org)
+API_ID = int(os.getenv("TELEGRAM_API_ID", "0"))
+API_HASH = os.getenv("TELEGRAM_API_HASH", "")
+
+# Bot username to chat with
+BOT_USERNAME = os.getenv("BOT_USERNAME", "telegram_summary_bot")
+
+# Session storage directory
+SESSION_DIR = os.getenv("SESSION_DIR", "/opt/telegram-web-client/sessions")
+
+# Server settings
+HOST = os.getenv("HOST", "0.0.0.0")
+PORT = int(os.getenv("PORT", "8000"))