feat(notifications): add multi-channel notification module with Email, FCM, templates, and event listeners

- Domain: NotificationLog/NotificationPreference entities, repositories, channel value object
- Infrastructure: EmailService (nodemailer/SMTP), FcmService (firebase-admin), TemplateService (Handlebars)
- Application: SendNotification CQRS command, UserRegistered + AgentVerified event listeners
- Presentation: NotificationsController with history, preferences, and templates endpoints
- Prisma: NotificationLog and NotificationPreference models with proper indexes
- Templates: Vietnamese notification templates for user.registered, agent.verified, listing.approved, inquiry.received, password.reset

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/api/src/modules/notifications/presentation/controllers/notifications.controller.ts

@@ -0,0 +1,70 @@
+import {
+  Controller,
+  Get,
+  Put,
+  Body,
+  Query,
+  UseGuards,
+  Inject,
+} from '@nestjs/common';
+import { AuthGuard } from '@nestjs/passport';
+import { CurrentUser } from '@modules/auth/presentation/decorators';
+import { type JwtPayload } from '@modules/auth';
+import {
+  NOTIFICATION_REPOSITORY,
+  type INotificationRepository,
+  NOTIFICATION_PREFERENCE_REPOSITORY,
+  type INotificationPreferenceRepository,
+} from '../../domain';
+import { TemplateService } from '../../infrastructure/services/template.service';
+import { IsBoolean, IsEnum, IsString } from 'class-validator';
+import { NotificationChannel as PrismaChannel } from '@prisma/client';
+
+class UpdatePreferenceDto {
+  @IsEnum(PrismaChannel)
+  channel!: PrismaChannel;
+
+  @IsString()
+  eventType!: string;
+
+  @IsBoolean()
+  enabled!: boolean;
+}
+
+@Controller('notifications')
+@UseGuards(AuthGuard('jwt'))
+export class NotificationsController {
+  constructor(
+    @Inject(NOTIFICATION_REPOSITORY)
+    private readonly notificationRepo: INotificationRepository,
+    @Inject(NOTIFICATION_PREFERENCE_REPOSITORY)
+    private readonly preferenceRepo: INotificationPreferenceRepository,
+    private readonly templateService: TemplateService,
+  ) {}
+
+  @Get('history')
+  async getHistory(
+    @CurrentUser() user: JwtPayload,
+    @Query('limit') limit?: number,
+  ) {
+    return this.notificationRepo.findByUserId(user.sub, limit ?? 50);
+  }
+
+  @Get('preferences')
+  async getPreferences(@CurrentUser() user: JwtPayload) {
+    return this.preferenceRepo.findByUserId(user.sub);
+  }
+
+  @Put('preferences')
+  async updatePreference(
+    @CurrentUser() user: JwtPayload,
+    @Body() dto: UpdatePreferenceDto,
+  ) {
+    return this.preferenceRepo.upsert(user.sub, dto.channel, dto.eventType, dto.enabled);
+  }
+
+  @Get('templates')
+  async getTemplates() {
+    return { templates: this.templateService.getTemplateKeys() };
+  }
+}