Refactor backend services and jail configuration

- Refactor action_config_service, filter_config_service, jail_config_service, and jail_service
- Add jail_socket utility module for socket communication
- Update test_jail_service with new test cases
- Update architecture and task documentation

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

backend/tests/test_services/test_jail_service.py

@@ -15,6 +15,7 @@ from app.models.geo import GeoDetail, GeoInfo
 from app.models.jail import JailDetailResponse, JailListResponse
 from app.services import ban_service, jail_service
 from app.services.jail_service import JailNotFoundError, JailOperationError
+from app.utils import jail_socket
 
 # ---------------------------------------------------------------------------
 # Helpers
@@ -75,6 +76,7 @@ def _patch_client(responses: dict[str, Any]) -> Any:
     stack = contextlib.ExitStack()
     stack.enter_context(patch("app.services.jail_service.Fail2BanClient", _FakeClient))
     stack.enter_context(patch("app.services.ban_service.Fail2BanClient", _FakeClient))
+    stack.enter_context(patch("app.utils.jail_socket.Fail2BanClient", _FakeClient))
     return stack
 
 
@@ -281,12 +283,12 @@ class TestLockInitialization:
 
     async def test_reload_all_lock_is_lazy_initialised(self) -> None:
         """The reload-all lock should be created lazily on first use."""
-        jail_service._reload_all_lock = None
+        jail_socket._reload_all_lock = None
 
-        lock = _ = jail_service._get_reload_all_lock()
+        lock = _ = jail_socket._get_reload_all_lock()
 
         assert isinstance(lock, asyncio.Lock)
-        assert jail_service._reload_all_lock is lock
+        assert jail_socket._reload_all_lock is lock
 
     async def test_backend_cmd_lock_is_lazy_initialised(self) -> None:
         """The backend capability probe lock should be created lazily on first use."""