The word "breached" in infrastructure monitoring was confusing users
as it implied a security breach. Renamed to "exceeded" which better
describes threshold violations (e.g. "threshold exceeded").
## Changes
- Renamed monitor status value from "breached" to "exceeded" across
server types, status service, queue helper, notification builder,
email subject lines, and MongoDB aggregation queries
- Renamed client types, status box/label components, translation key,
and infrastructure page props to match
- Added DB migration (0005) to update existing monitors with the old
status value
- Merge duplicate react-router-dom imports into one
- Replace useIsAdmin + useIsSuperAdmin + useSelector with single useSelector
- Remove redundant !includes("superadmin") check from canDeleteUser
## Changes
- Add DELETE /api/v1/auth/users/:userId endpoint (admin + superadmin)
- Add deleteUserById service method with role hierarchy enforcement
- Superadmins can remove admins and regular users
- Admins can only remove regular users
- No one can remove superadmins, demo users, or themselves via this endpoint
- Add "Remove user" button with confirmation dialog on edit user page
- Allow admins to view user details and access the edit user page
- Add i18n strings for remove user button and confirmation dialog
## Access control
- superadmin -> can remove admin, user
- admin -> can remove user only
- admin cannot remove superadmin or other admins (enforced on both backend and frontend)
## Changes
- Replace MUI default blue-tinted dark background with neutral grays
(#151518 for default, #1c1c21 for paper/cards)
- Remove decorative blue/purple SVG blob overlay from dark mode background
## Benefits
- Dark mode now has a clean, neutral gray appearance instead of a blue tint