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>

Docs/Tasks.md

@@ -1,26 +1,3 @@
-### T-06 · Eliminate `AppState` Protocol / `ApplicationContext` dataclass redundancy
-
-**Where found:** `backend/app/dependencies.py` — `AppState` Protocol (lines ~40–60) and `ApplicationContext` dataclass (lines ~62–75) describe identical fields.
-
-**Why this is needed:** Every new field must be added to both. The Protocol is only used for a single `cast()` call inside `_build_app_context`. Maintenance burden with no benefit.
-
-**Goal:** One typed representation. Remove `AppState` Protocol; cast directly or use `ApplicationContext`.
-
-**What to do:**
-1. Delete the `AppState` Protocol class.
-2. Replace `state = cast("AppState", request.app.state)` with `state = request.app.state` (type: ignore or use `ApplicationState` directly since it's the concrete type set in `create_app`).
-3. Access fields from `state` directly using the `ApplicationState` / `RuntimeState` types.
-
-**Possible traps and issues:**
-- `mypy` / pyright may report type errors on `request.app.state` accesses — use `cast(ApplicationState, request.app.state)` once, then access typed.
-- Ensure all fields accessed in `_build_app_context` are present on `ApplicationState`.
-
-**Docs changes needed:** None.
-
-**Doc references:** `backend/app/dependencies.py`, `backend/app/utils/runtime_state.py`
-
----
-
 ### T-07 · Break cross-service import: `jail_config_service` imports `jail_service`
 
 **Where found:** `backend/app/services/jail_config_service.py` — `import app.services.jail_service as jail_service`