41434b536b
## Summary - New **Back office** tab at `/admin`, per-org detail page at `/admin/back-office/orgs/:orgId` designed to host future per-org admin actions (project count, delete account, YC deals). - First action: edit an organization's API rate limit — tokenBucket override (refill rate, interval, max tokens), with a live plain-English preview (e.g. *"1,500 requests per minute · 750 request burst allowance"*). Writes are audit-logged via the server logger. - Cleanup: removed unused `v2?` / `v3?` columns from the admin orgs list (display only — Prisma select untouched). ## Test plan - [ ] Back office tab visible in admin nav and highlighted when on a sub-route - [ ] `/admin/orgs` shows a Back office "Open" link per row; no v2/v3 columns - [ ] Empty state at `/admin/back-office` links back to `/admin/orgs` - [ ] Detail page renders the effective rate limit in view mode; Edit reveals the form - [ ] Save writes `Organization.apiRateLimiterConfig`, returns to view mode, shows "Rate limit saved." banner - [ ] Invalid values surface inline field errors and keep edit mode - [ ] Non-admins hitting any new route are redirected to `/` - [ ] Server logs show `admin.backOffice.rateLimit` info line per mutation