Clean up unused imports and remove completed task

- Remove TASK-016 from Docs/Tasks.md (completed)
- Remove unused imports from protocols.py (Iterable, BanIpCount)
- Remove unused imports from raw_config_io_service.py (asyncio, ConfigDirError, ConfigFileExistsError, ConfFileEntry)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

backend/app/repositories/protocols.py

@@ -6,14 +6,14 @@ module implementations, making the backend easier to test and extend.
 
 from __future__ import annotations
 
-from collections.abc import Iterable, Sequence
+from collections.abc import Sequence
 from typing import Any, Protocol
 
 import aiosqlite
 
 from app.models.auth import Session
 from app.models.ban import BanOrigin
-from app.repositories.fail2ban_db_repo import BanIpCount, BanRecord, HistoryRecord, JailBanCount
+from app.repositories.fail2ban_db_repo import BanRecord, HistoryRecord, JailBanCount
 from app.repositories.geo_cache_repo import GeoCacheRow
 from app.repositories.import_log_repo import ImportLogRow