Change sys to admin

[idotta]

Create get all tenants endpoint

---

Note

Introduces an Admin API surface and deprecates the old System (/sys) routes.

• Rename and regroup endpoints from /sys to /admin via new AdminEndpoints; update routing, DI registrations, docs, sample UI/JS, and tests accordingly
• Move system-related features into Idmt.Plugin.Features.Admin (create/delete tenant, grant/revoke/list user tenants, system info) and update MapIdmtEndpoints
• Add GET /admin/tenants to list all tenants, returning TenantInfoResponse[] (now includes IsActive)
• Validation and policy tweaks: enforce tenant identifier format (Validators.IsValidTenantIdentifier) in CreateTenant; forbid deleting default tenant; CreateTenant requires RequireSysUser, DeleteTenant now RequireSysAdmin; keep system/info behind RequireSysUser
• Update seeding to use Admin create-tenant handler; minor cleanup in ForgotPassword and tests

^{Written by Cursor Bugbot for commit f14be17. This will update automatically on new commits. Configure here.}

[cursor]

This PR is being reviewed by Cursor Bugbot

Details

You are on the Bugbot Free tier. On this plan, Bugbot will review limited PRs each billing cycle.

To receive Bugbot reviews on all of your PRs, visit the Cursor dashboard to activate Pro and start your 14-day free trial.