feat(api): add health check endpoints with @nestjs/terminus

Add HealthModule with /health (liveness) and /ready (readiness) probes.
Readiness checks DB (Prisma) and Redis connectivity.
Replaces the basic /health endpoint in AppController.

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

apps/api/src/app.module.ts

@@ -6,6 +6,7 @@ import { SentryGlobalFilter, SentryModule } from '@sentry/nestjs/setup';
 import { AdminModule } from '@modules/admin';
 import { AnalyticsModule } from '@modules/analytics';
 import { AuthModule } from '@modules/auth';
+import { HealthModule } from '@modules/health';
 import { ListingsModule } from '@modules/listings';
 import { McpIntegrationModule } from '@modules/mcp';
 import { HttpMetricsInterceptor, MetricsModule } from '@modules/metrics';
@@ -25,6 +26,7 @@ import { AppController } from './app.controller';
     SentryModule.forRoot(),
     CqrsModule.forRoot(),
     SharedModule,
+    HealthModule,
     AuthModule,
     ListingsModule,
     ReviewsModule,