feat(stage-1): inactive jail discovery and activation

- Backend: config_file_service.py parses jail.conf/jail.local/jail.d/*
  following fail2ban merge order; discovers jails not running in fail2ban
- Backend: 3 new API endpoints (GET /jails/inactive, POST /jails/{name}/activate,
  POST /jails/{name}/deactivate); moved /jails/inactive before /jails/{name}
  to fix route-ordering conflict
- Frontend: ActivateJailDialog component with optional parameter overrides
- Frontend: JailsTab extended with inactive jail list and InactiveJailDetail pane
- Frontend: JailsPage JailOverviewSection shows inactive jails with toggle
- Tests: 57 service tests + 16 router tests for all new endpoints (all pass)
- Docs: Features.md, Architekture.md, Tasks.md updated; Tasks 1.1-1.5 marked done

frontend/src/api/endpoints.ts

@@ -61,9 +61,14 @@ export const ENDPOINTS = {
   // Configuration
   // -------------------------------------------------------------------------
   configJails: "/config/jails",
+  configJailsInactive: "/config/jails/inactive",
   configJail: (name: string): string => `/config/jails/${encodeURIComponent(name)}`,
   configJailLogPath: (name: string): string =>
     `/config/jails/${encodeURIComponent(name)}/logpath`,
+  configJailActivate: (name: string): string =>
+    `/config/jails/${encodeURIComponent(name)}/activate`,
+  configJailDeactivate: (name: string): string =>
+    `/config/jails/${encodeURIComponent(name)}/deactivate`,
   configGlobal: "/config/global",
   configReload: "/config/reload",
   configRegexTest: "/config/regex-test",