feat: extract admin account management rework from PR 124 (#138)

* feat: reorganize admin panel around accounts

* feat: expand admin customer account controls

* feat: add admin account detail management

* fix: remove unused admin account icon import

* refactor: design critique fixes for account pages

- Admin accounts: replace dense card grid with compact DataTable
- Account settings: remove redundant hero card, stat grid, header pills
- Fix bg-accent (orange) misuse on decorative elements across 7 files
- Add ConfirmButton for destructive actions (deactivate, remove member)
- Replace single-field modals with inline editing (plan, trial)
- Add contextual help: display code tooltip, improved empty states
- Non-owner aside explanation for hidden owner-only sections
- Admin sidebar: group 11 items into 5 labeled sections
- Rename UsersPage.tsx → AccountsPage.tsx to match route
- Fix border radius consistency, hide zero-count badges

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: use get_admin_db for all new admin account endpoints

All admin endpoints query across tenants without a tenant context.
get_db (app-role, subject to RLS) was never imported and would crash
at runtime — replace all 6 occurrences with get_admin_db (BYPASSRLS).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/api/admin.ts

@@ -2,6 +2,11 @@ import api from './client'
 import type {
   DashboardMetrics,
   ActivityEntry,
+  AdminUserListResponse,
+  AdminAccountListResponse,
+  AdminAccountDetailResponse,
+  AdminAccountCreate,
+  AdminAccountUpdate,
   AuditLogListResponse,
   PlanLimitConfig,
   AccountOverrideResponse,
@@ -78,7 +83,15 @@ export const adminApi = {
   createUser: (data: AdminUserCreate) =>
     api.post<AdminUserCreateResponse>('/admin/users', data).then(r => r.data),
   listUsers: (params?: Record<string, unknown>) =>
-    api.get('/admin/users', { params }).then(r => r.data),
+    api.get<AdminUserListResponse>('/admin/users', { params }).then(r => r.data),
+  listAccounts: (params?: Record<string, unknown>) =>
+    api.get<AdminAccountListResponse>('/admin/accounts', { params }).then(r => r.data),
+  createAccount: (data: AdminAccountCreate) =>
+    api.post<AdminAccountDetailResponse>('/admin/accounts', data).then(r => r.data),
+  getAccountDetail: (id: string, params?: Record<string, unknown>) =>
+    api.get<AdminAccountDetailResponse>(`/admin/accounts/${id}`, { params }).then(r => r.data),
+  updateAccount: (id: string, data: AdminAccountUpdate) =>
+    api.put<AdminAccountDetailResponse>(`/admin/accounts/${id}`, data).then(r => r.data),
   getUser: (id: string) =>
     api.get(`/admin/users/${id}`).then(r => r.data),
   updateUserRole: (id: string, role: string) =>
@@ -119,6 +132,10 @@ export const adminApi = {
     api.put(`/admin/users/${id}/subscription/plan`, { plan }).then(r => r.data),
   extendUserTrial: (id: string, days: number) =>
     api.put(`/admin/users/${id}/subscription/extend-trial`, { days }).then(r => r.data),
+  updateAccountSubscriptionPlan: (id: string, plan: string) =>
+    api.put(`/admin/accounts/${id}/subscription/plan`, { plan }).then(r => r.data),
+  extendAccountTrial: (id: string, days: number) =>
+    api.put(`/admin/accounts/${id}/subscription/extend-trial`, { days }).then(r => r.data),
 
   // Invite Codes
   listInviteCodes: (params?: Record<string, unknown>) =>