Replaces the three REST count calls with a single Prometheus scrape that
auto-refreshes every 15s, surfaces queue/worker/in-flight/RSS/version/uptime
as featured cards, and tucks counters and Go runtime stats under a
"Show more metrics" Collapse.
Introduce a UserQuota field on the User model to hold admin-controlled
limits and flags that the user cannot modify. Only checker-related
fields are defined for now (max checks per day, retention days,
inactivity pause days, scheduling kill switch); future paid-plan
attributes will be added here later.
The user-facing API only exposes settings updates and account deletion,
so Quota cannot be written through it. Updates go through the existing
admin user PUT endpoint, with a new editor card in the admin UI under
/users/[uid].
Add all checker UI pages and components:
- Checker list, config, schedule, and rules pages
- Execution list, detail, results, and rules pages
- Sidebar components for domain/service checker status
- Run check modal with option overrides and rule selection
- Domain-scoped and service-scoped check routes
- Admin pages for checker configuration and scheduler management
- Header navigation link for checkers section
