Add per-user quotas (max instances, vCPU, RAM, disk) enforced at deploy
time and surfaced to users self-service.
Backend:
- UserQuota model (one-to-one, NULL = unlimited) + migration #28
- quota_service: usage from vm_instances cache, check_quota raises 429
- enforce in VM (templates.py) and LXC (lxc.py) deploy paths
- RBAC quota:view / quota:manage, granted to admin
- admin API GET/PUT /admin/api/users/{id}/quota
- self-service GET /settings/api/quota
- tighten VM list isolation via can_view_all_instances
Frontend:
- admin quota dialog in UsersPage with usage bars
- quota card on Settings page (own limits)
- remaining-quota hint in CreateInstanceWizard config step
- useUserQuota/useSetUserQuota, useMyQuota hooks; RU/EN locales
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>