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/bot/fsm.py

@@ -1,8 +1,10 @@
-"""FSM storage factory. In-memory for now; Postgres-backed storage that survives restarts arrives with the DB (#5)."""
+"""FSM storage factory: dialog state lives in the DB and survives restarts (SPEC M-4)."""
 
 from aiogram.fsm.storage.base import BaseStorage
-from aiogram.fsm.storage.memory import MemoryStorage
+
+from app.bot.fsm_storage import SqlStorage
+from app.db.session import SessionMaker
 
 
-def make_storage() -> BaseStorage:
-    return MemoryStorage()
+def make_storage(sessions: SessionMaker) -> BaseStorage:
+    return SqlStorage(sessions)

app/bot/fsm_storage.py

@@ -0,0 +1,54 @@
+"""aiogram FSM storage on top of the `fsm_state` table — dialog state survives bot restarts (SPEC M-4)."""
+
+from collections.abc import Mapping
+from typing import Any
+
+from aiogram.fsm.state import State
+from aiogram.fsm.storage.base import BaseStorage, StateType, StorageKey
+
+from app.db.models import FsmState
+from app.db.session import SessionMaker
+
+
+def key_to_str(key: StorageKey) -> str:
+    parts = (key.bot_id, key.chat_id, key.user_id, key.thread_id, key.business_connection_id, key.destiny)
+    return ":".join("" if p is None else str(p) for p in parts)
+
+
+class SqlStorage(BaseStorage):
+    def __init__(self, sessions: SessionMaker) -> None:
+        self._sessions = sessions
+
+    async def set_state(self, key: StorageKey, state: StateType = None) -> None:
+        value = state.state if isinstance(state, State) else state
+        await self._write(key, state=value)
+
+    async def get_state(self, key: StorageKey) -> str | None:
+        async with self._sessions() as session:
+            row = await session.get(FsmState, key_to_str(key))
+            return row.state if row else None
+
+    async def set_data(self, key: StorageKey, data: Mapping[str, Any]) -> None:
+        await self._write(key, data=dict(data))
+
+    async def get_data(self, key: StorageKey) -> dict[str, Any]:
+        async with self._sessions() as session:
+            row = await session.get(FsmState, key_to_str(key))
+            return dict(row.data) if row else {}
+
+    async def close(self) -> None:
+        pass  # the engine is owned and disposed by the app
+
+    async def _write(self, key: StorageKey, **fields: Any) -> None:
+        async with self._sessions.begin() as session:
+            row = await session.get(FsmState, key_to_str(key))
+            state = fields.get("state", row.state if row else None)
+            data = fields.get("data", row.data if row else {})
+            if state is None and not data:
+                if row is not None:
+                    await session.delete(row)  # empty state: keep the table small
+                return
+            if row is None:
+                session.add(FsmState(key=key_to_str(key), state=state, data=data))
+            else:
+                row.state, row.data = state, data