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/services/raw_config_io_service.py

@@ -15,11 +15,8 @@ traversal attacks.
 
 from __future__ import annotations
 
-import asyncio
 from app.utils.async_utils import run_blocking
 from app.exceptions import (
-    ConfigDirError,
-    ConfigFileExistsError,
     ConfigFileNameError,
     ConfigFileNotFoundError,
     ConfigFileWriteError,
@@ -34,7 +31,6 @@ import structlog
 from app.models.file_config import (
     ConfFileContent,
     ConfFileCreateRequest,
-    ConfFileEntry,
     ConfFilesResponse,
     ConfFileUpdateRequest,
     JailConfigFile,