Blocking: count Advanced Blocking, Dashboard layout and KPI cards

- Status, sidebar mark and header treat a server that blocks with the
  Advanced Blocking app as blocking, per server behind the hub.
- Overview panel summarising the app's groups; Lists and Rules show and
  edit the app's list URLs and rules (read, change one field, write back).
- Block List Domains adds the app's list domains, counted by the hub
  (hub/blocking/app-lists/count, public hosts only unless
  HUB_LISTS_ALLOW_PRIVATE=1) or by the browser where CORS allows.
- Header and KPI cards follow the Dashboard: selector in the chrome slot,
  Compare servers in the header actions, period under the title, StatCard
  tiles without sparklines.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

hub/routes.ts

@@ -185,6 +185,8 @@ export const ROUTES: Record<string, Route> = {
   'hub/settings/baseline/save': writeAll('admin'),
   'hub/settings/overrides/save': writeAll('admin'),
   'hub/settings/apply': writeAll('admin'),
+  // The domains in an Advanced Blocking app's block lists, counted by the hub (app-lists.ts). One server's app.
+  'hub/blocking/app-lists/count': readOne(),
   'hub/blocking/lists/compare': read('admin'),
   'hub/blocking/lists/preview': read('admin'),
   'hub/blocking/lists/baseline/import': writeAll('admin'),