Stage 7: configuration view — backend service, routers, tests, and frontend

- config_service.py: read/write jail config via asyncio.gather, global
  settings, in-process regex validation, log preview via _read_tail_lines
- server_service.py: read/write server settings, flush logs
- config router: 9 endpoints for jail/global config, regex-test,
  logpath management, log preview
- server router: GET/PUT settings, POST flush-logs
- models/config.py expanded with JailConfig, GlobalConfigUpdate,
  LogPreview* models
- 285 tests pass (68 new), ruff clean, mypy clean (44 files)
- Frontend: types/config.ts, api/config.ts, hooks/useConfig.ts,
  ConfigPage.tsx full implementation (Jails accordion editor,
  Global config, Server settings, Regex Tester with preview)
- Fixed pre-existing frontend lint: JSX.Element → React.JSX.Element
  (10 files), void/promise patterns in useServerStatus + useJails,
  no-misused-spread in client.ts, eslint.config.ts self-excluded

backend/app/main.py

@@ -33,7 +33,7 @@ from starlette.middleware.base import BaseHTTPMiddleware
 
 from app.config import Settings, get_settings
 from app.db import init_db
-from app.routers import auth, bans, dashboard, geo, health, jails, setup
+from app.routers import auth, bans, config, dashboard, geo, health, jails, server, setup
 from app.tasks import health_check
 
 # ---------------------------------------------------------------------------
@@ -276,5 +276,7 @@ def create_app(settings: Settings | None = None) -> FastAPI:
     app.include_router(jails.router)
     app.include_router(bans.router)
     app.include_router(geo.router)
+    app.include_router(config.router)
+    app.include_router(server.router)
 
     return app