feat(admin): show user subscription plan and token quota in user pages

Expose active subscription summary on user list and detail so operators can see plan type, total/used/remaining tokens without opening billing subscriptions.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/types.ts

@@ -44,8 +44,17 @@ export type AuthStatus = {
   unrestricted?: boolean;
 };
 
+export type UserSubscriptionSummary = {
+  planType: string;
+  status: 'active' | 'expired' | 'cancelled';
+  periodTokensLimit: number;
+  periodTokensUsed: number;
+  expiresAt: number;
+};
+
 export type AdminUserRow = PortalUser & {
   billingFormula?: 'A' | 'B';
+  subscription?: UserSubscriptionSummary | null;
   createdAt: number;
   updatedAt: number;
 };