feat: implement full admin panel with dashboard, user management, and platform settings

Adds complete super_admin panel with 9 pages and account owner categories page.
Backend includes 5 new DB tables, ~25 API endpoints, settings manager with
in-memory cache, and 29 integration tests. Frontend includes reusable admin
components (DataTable, Pagination, ActionMenu, etc.) with code-split lazy loading.

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

frontend/src/types/admin.ts

@@ -0,0 +1,130 @@
+// Admin panel types - aligned with backend schemas/admin.py
+
+export interface DashboardMetrics {
+  total_users: number
+  active_subscriptions: number
+  paid_accounts: number
+  total_trees: number
+}
+
+export interface ActivityEntry {
+  id: string
+  user_email: string | null
+  action: string
+  resource_type: string
+  resource_id: string | null
+  details: Record<string, unknown> | null
+  ip_address: string | null
+  created_at: string
+}
+
+export interface AuditLogEntry {
+  id: string
+  user_id: string
+  user_email: string | null
+  action: string
+  resource_type: string
+  resource_id: string | null
+  details: Record<string, unknown> | null
+  ip_address: string | null
+  created_at: string
+}
+
+export interface AuditLogListResponse {
+  items: AuditLogEntry[]
+  total: number
+  page: number
+  per_page: number
+}
+
+export interface PlanLimitConfig {
+  plan: string
+  max_trees: number | null
+  max_sessions_per_month: number | null
+  max_users: number | null
+  custom_branding: boolean
+  priority_support: boolean
+  export_formats: string[]
+}
+
+export interface AccountOverrideResponse {
+  id: string
+  account_id: string
+  account_name: string | null
+  account_display_code: string | null
+  override_max_trees: number | null
+  override_max_sessions_per_month: number | null
+  override_max_users: number | null
+  note: string | null
+  created_at: string
+  updated_at: string
+}
+
+export interface PlanDefaultEntry {
+  plan: string
+  enabled: boolean
+}
+
+export interface FeatureFlagResponse {
+  id: string
+  flag_key: string
+  display_name: string
+  description: string | null
+  plan_defaults: PlanDefaultEntry[]
+  created_at: string
+}
+
+export interface AccountFeatureOverrideResponse {
+  id: string
+  account_id: string
+  account_display_code: string | null
+  flag_id: string
+  flag_key: string | null
+  flag_display_name: string | null
+  enabled: boolean
+  note: string | null
+  created_at: string
+}
+
+export interface AdminCategory {
+  id: string
+  name: string
+  slug: string
+  description: string | null
+  account_id: string | null
+  tree_count: number
+}
+
+// Request types
+export interface AccountOverrideCreate {
+  account_display_code: string
+  override_max_trees?: number | null
+  override_max_sessions_per_month?: number | null
+  override_max_users?: number | null
+  note?: string | null
+}
+
+export interface FeatureFlagCreate {
+  flag_key: string
+  display_name: string
+  description?: string | null
+}
+
+export interface PlanDefaultUpdate {
+  plan: string
+  flag_id: string
+  enabled: boolean
+}
+
+export interface AccountFeatureOverrideCreate {
+  account_display_code: string
+  flag_id: string
+  enabled: boolean
+  note?: string | null
+}
+
+export interface GlobalCategoryCreate {
+  name: string
+  slug: string
+  description?: string | null
+}

frontend/src/types/index.ts

@@ -8,6 +8,7 @@ export * from './category'
 export * from './folder'
 export * from './step'
 export type { Account, Subscription, PlanLimits, SubscriptionDetails, AccountInvite, AccountMember } from './account'
+export * from './admin'
 
 // API response wrapper types
 export interface PaginatedResponse<T> {