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/package.json

@@ -26,8 +26,11 @@
     "bcrypt": "^6.0.0",
     "class-transformer": "^0.5.1",
     "class-validator": "^0.15.1",
+    "firebase-admin": "^13.7.0",
+    "handlebars": "^4.7.9",
     "helmet": "^8.1.0",
     "ioredis": "^5.4.0",
+    "nodemailer": "^8.0.5",
     "passport": "^0.7.0",
     "passport-jwt": "^4.0.1",
     "passport-local": "^1.0.0",
@@ -35,7 +38,8 @@
     "pino-pretty": "^13.0.0",
     "reflect-metadata": "^0.2.0",
     "rxjs": "^7.8.0",
-    "sanitize-html": "^2.17.2"
+    "sanitize-html": "^2.17.2",
+    "typesense": "^3.0.5"
   },
   "devDependencies": {
     "@nestjs/cli": "^11.0.0",
@@ -44,6 +48,7 @@
     "@types/bcrypt": "^6.0.0",
     "@types/express": "^5.0.0",
     "@types/node": "^22.0.0",
+    "@types/nodemailer": "^8.0.0",
     "@types/passport-jwt": "^4.0.1",
     "@types/passport-local": "^1.0.38",
     "@types/sanitize-html": "^2.16.1",