Harden fail2ban integration and mark task complete

backend/tests/conftest.py

@@ -7,14 +7,8 @@ infrastructure.
 
 from __future__ import annotations
 
-import sys
 from pathlib import Path
 
-# Ensure the bundled fail2ban package is importable.
-_FAIL2BAN_MASTER: Path = Path(__file__).resolve().parents[2] / "fail2ban-master"
-if str(_FAIL2BAN_MASTER) not in sys.path:
-    sys.path.insert(0, str(_FAIL2BAN_MASTER))
-
 import aiosqlite
 import pytest
 from httpx import ASGITransport, AsyncClient