Add user membership and admin customer management APIs.

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

prisma/migrations/20260928160000_user_membership/migration.sql

@@ -0,0 +1,5 @@
+-- CreateEnum
+CREATE TYPE "Membership" AS ENUM ('regular', 'premium');
+
+-- AlterTable
+ALTER TABLE "User" ADD COLUMN "membership" "Membership" NOT NULL DEFAULT 'regular';

prisma/schema.prisma

@@ -13,6 +13,11 @@ enum UserRole {
   SUPER_ADMIN
 }
 
+enum Membership {
+  regular
+  premium
+}
+
 enum StoreStatus {
   pending
   active
@@ -63,8 +68,9 @@ model User {
   about        String?
   avatarUrl    String?
   avatarKey    String?
-  role         UserRole @default(CUSTOMER)
-  disabled     Boolean  @default(false)
+  role         UserRole   @default(CUSTOMER)
+  membership   Membership @default(regular)
+  disabled     Boolean    @default(false)
   createdAt    DateTime @default(now())
   updatedAt    DateTime @updatedAt