feat(bot): модель данных, миграции Alembic, FSM в БД, TTL-чистка

- app/db/models.py: 13 таблиц (ARCHITECTURE §2.10); перечисления — VARCHAR + CHECK,
  JSON → JSONB на Postgres, BIGINT/INTEGER-ключи для SQLite
- миграция 0001 (автогенерация + ручная чистка: импорт sa.Text, дубли CHECK)
- миграции применяются при старте бота программно (app.db.migrate), script_location из пакета
- SqlStorage: FSM aiogram поверх fsm_state — состояние переживает рестарт (перенесено из #4)
- cleanup_loop: истёкшие черновики, снимки контейнеров и попытки входа старше суток
- тесты: upgrade/downgrade, дрейф моделей и миграций, CHECK, CASCADE, FSM, чистка

Refs #5

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/main.py

@@ -11,6 +11,9 @@ from app.bot.fsm import make_storage
 from app.bot.middlewares.access import AccessMiddleware
 from app.bot.routers.common import build_router
 from app.config import Settings
+from app.db.maintenance import cleanup_loop
+from app.db.migrate import upgrade
+from app.db.session import SessionMaker, make_engine, make_sessionmaker
 from app.health import heartbeat
 from app.logs_setup import setup_logging
 from app.texts import Texts, load_texts
@@ -18,13 +21,13 @@ from app.texts import Texts, load_texts
 log = logging.getLogger("tgit")
 
 
-def build_dispatcher(settings: Settings, texts: Texts) -> Dispatcher:
+def build_dispatcher(settings: Settings, texts: Texts, sessions: SessionMaker) -> Dispatcher:
     admin_ids = settings.access.admin_ids
 
     async def is_member(tg_id: int) -> bool:
         return tg_id in admin_ids
 
-    dp = Dispatcher(storage=make_storage())
+    dp = Dispatcher(storage=make_storage(sessions))
     access = AccessMiddleware(is_member, texts)
     # Outer middleware: runs before filters, so nothing — not even a stale button — reaches a handler unchecked.
     dp.message.outer_middleware(access)
@@ -35,18 +38,27 @@ def build_dispatcher(settings: Settings, texts: Texts) -> Dispatcher:
 
 async def run(settings: Settings) -> None:
     texts = load_texts(settings.runtime.config_dir)
-    dp = build_dispatcher(settings, texts)
+    engine = make_engine(settings.database.url)
+    await upgrade(engine)
+    sessions = make_sessionmaker(engine)
+    dp = build_dispatcher(settings, texts, sessions)
     rt = settings.runtime
-    beat = asyncio.create_task(heartbeat(rt.heartbeat_file, rt.heartbeat_interval))
+    background = [
+        asyncio.create_task(heartbeat(rt.heartbeat_file, rt.heartbeat_interval)),
+        asyncio.create_task(cleanup_loop(sessions)),
+    ]
     bot = Bot(settings.telegram.bot_token.get_secret_value())
     log.info("tgit %s starting, %d bootstrap admin(s)", __version__, len(settings.access.admin_ids))
     try:
         await dp.start_polling(bot, handle_signals=True)
     finally:
-        beat.cancel()
-        with contextlib.suppress(asyncio.CancelledError):
-            await beat
+        for task in background:
+            task.cancel()
+        for task in background:
+            with contextlib.suppress(asyncio.CancelledError):
+                await task
         await bot.session.close()
+        await engine.dispose()
         log.info("tgit stopped")