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>

Docs/Tasks.md

@@ -1,32 +1,3 @@
-## TASK-016 — `delete_log_path` query parameter unvalidated
-
-**Severity:** Medium
-
-### Where found
-`backend/app/routers/jail_config.py` — `DELETE /api/config/jails/{name}/logpath` — `log_path: str = Query(...)`.
-
-### Why this is needed
-The `log_path` query parameter is passed directly to the fail2ban socket command `["set", name, "dellogpath", log_path]` without any path validation. An attacker could pass traversal strings or paths to sensitive files, instructing fail2ban to stop monitoring them and potentially confusing fail2ban's internal state.
-
-### Goal
-Apply the same allowlist validation as `add_log_path` (TASK-014) to `delete_log_path`.
-
-### What to do
-1. Extract the log path validation logic from TASK-014 into a shared helper function in `backend/app/utils/path_utils.py` (e.g., `validate_log_path(path: str, allowed_dirs: list[str]) -> str`).
-2. Call the helper from both `AddLogPathRequest` validator and the `delete_log_path` route handler.
-3. Return 422 with a descriptive error if validation fails.
-
-### Possible traps and issues
-- Query parameters cannot have Pydantic field validators directly in FastAPI — use a `Depends` dependency that validates and returns the resolved path, or validate explicitly at the start of the route handler.
-
-### Docs changes needed
-- `Backend-Development.md` — path validation helper usage.
-
-### Doc references
-- [Backend-Development.md](Backend-Development.md) — input validation patterns
-
----
-
 ## TASK-017 — `ip LIKE ?` without escaping `%` and `_` wildcards
 
 **Severity:** Medium