feat: complete admin backend controllers and services

- AdminPlansController & Service (CRUD, reorder)
- AdminPaymentMethodsController & Service (CRUD, reorder)
- AdminPaymentsController & Service (verify, reject, pending count)
- AdminUsersController & Service (search, suspend, grant pro access, stats)
- AdminConfigController & Service (dynamic config management)
- Wire all controllers into AdminModule
- Import AdminModule in AppModule

Admin API Routes:
- GET/POST/PUT/DELETE /admin/plans
- GET/POST/PUT/DELETE /admin/payment-methods
- GET /admin/payments (with status filter)
- POST /admin/payments/:id/verify
- POST /admin/payments/:id/reject
- GET /admin/users (with search)
- POST /admin/users/:id/grant-pro
- GET/POST/DELETE /admin/config

All routes protected by AuthGuard + AdminGuard

apps/api/dist/admin/admin-config.service.js

@@ -0,0 +1,68 @@
+"use strict";
+var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
+    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
+    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
+    else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
+    return c > 3 && r && Object.defineProperty(target, key, r), r;
+};
+var __metadata = (this && this.__metadata) || function (k, v) {
+    if (typeof Reflect === "object" && typeof Reflect.metadata === "function") return Reflect.metadata(k, v);
+};
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.AdminConfigService = void 0;
+const common_1 = require("@nestjs/common");
+const prisma_service_1 = require("../prisma/prisma.service");
+let AdminConfigService = class AdminConfigService {
+    prisma;
+    constructor(prisma) {
+        this.prisma = prisma;
+    }
+    async findAll(category) {
+        return this.prisma.appConfig.findMany({
+            where: category ? { category } : undefined,
+            orderBy: { category: 'asc' },
+        });
+    }
+    async findOne(key) {
+        return this.prisma.appConfig.findUnique({
+            where: { key },
+        });
+    }
+    async upsert(key, data, updatedBy) {
+        return this.prisma.appConfig.upsert({
+            where: { key },
+            update: {
+                ...data,
+                updatedBy,
+                updatedAt: new Date(),
+            },
+            create: {
+                key,
+                ...data,
+                updatedBy,
+            },
+        });
+    }
+    async delete(key) {
+        return this.prisma.appConfig.delete({
+            where: { key },
+        });
+    }
+    async getByCategory() {
+        const configs = await this.prisma.appConfig.findMany();
+        const grouped = configs.reduce((acc, config) => {
+            if (!acc[config.category]) {
+                acc[config.category] = [];
+            }
+            acc[config.category].push(config);
+            return acc;
+        }, {});
+        return grouped;
+    }
+};
+exports.AdminConfigService = AdminConfigService;
+exports.AdminConfigService = AdminConfigService = __decorate([
+    (0, common_1.Injectable)(),
+    __metadata("design:paramtypes", [prisma_service_1.PrismaService])
+], AdminConfigService);
+//# sourceMappingURL=admin-config.service.js.map