Add multi-user features: i18n, payments, multi-model AI, focus areas

Replace single report type with composable analysis: depth levels
(basic/standard/full) + focus area multi-select (psychology, business,
marketing, content, audience, sentiment). Multi-step inline keyboard
flow guides users through selection.

- i18n: English + Russian, auto-detect from Telegram, /lang override
- AI providers: Anthropic + OpenRouter via AIClient abstraction
- Telegram Stars payments with per-depth pricing and free trial
- SQLite (aiosqlite) for users, analyses, payments tracking
- User middleware for auto-registration and language detection
- Report persistence: save .md locally, offer file download
- New commands: /features, /prices, /lang
- Composable prompt system: depth modifiers + focus area fragments

bot/__main__.py

@@ -6,7 +6,9 @@ from aiogram import Bot, Dispatcher
 from telethon import TelegramClient
 
 from bot.config import settings
-from bot.handlers import analyze, start
+from bot.db.engine import get_db, close_db
+from bot.handlers import analyze, features, lang, payment, prices, start
+from bot.middleware.user_middleware import UserMiddleware
 
 SESSION_PATH = "/app/data/analyzer_session"
 
@@ -30,6 +32,10 @@ async def login() -> None:
 
 
 async def main() -> None:
+    # Init database
+    await get_db()
+    log.info("Database initialized")
+
     telethon_client = TelegramClient(
         SESSION_PATH,
         settings.telegram_api_id,
@@ -46,11 +52,19 @@ async def main() -> None:
     log.info("Telethon client started")
 
     bot = Bot(token=settings.bot_token)
-    # Attach telethon client to bot instance for handler access
     bot._telethon_client = telethon_client  # type: ignore[attr-defined]
 
     dp = Dispatcher()
+
+    # Register middleware
+    dp.update.middleware(UserMiddleware())
+
+    # Register routers — payment.pre_checkout must come before analyze
     dp.include_router(start.router)
+    dp.include_router(lang.router)
+    dp.include_router(features.router)
+    dp.include_router(prices.router)
+    dp.include_router(payment.router)
     dp.include_router(analyze.router)
 
     log.info("Starting bot polling...")
@@ -58,6 +72,7 @@ async def main() -> None:
         await dp.start_polling(bot)
     finally:
         await telethon_client.disconnect()
+        await close_db()
 
 
 if __name__ == "__main__":