Fix backend tests by using per-test temp config dir, align router mocks to service modules, fix log tail helper reference, and add JailNotFoundError.name

backend/tests/conftest.py

@@ -37,9 +37,15 @@ def test_settings(tmp_path: Path) -> Settings:
     Returns:
         A :class:`~app.config.Settings` instance with overridden paths.
     """
+    config_dir = tmp_path / "fail2ban"
+    (config_dir / "jail.d").mkdir(parents=True)
+    (config_dir / "filter.d").mkdir(parents=True)
+    (config_dir / "action.d").mkdir(parents=True)
+
     return Settings(
         database_path=str(tmp_path / "test_bangui.db"),
         fail2ban_socket="/tmp/fake_fail2ban.sock",
+        fail2ban_config_dir=str(config_dir),
         session_secret="test-secret-key-do-not-use-in-production",
         session_duration_minutes=60,
         timezone="UTC",