feat(api): add inquiries, leads, and agents modules for Agent Portal

Build three new DDD modules following existing CQRS patterns:
- Inquiries: CRUD endpoints for buyer consultation requests with agent notification support
- Leads: Full lead lifecycle management with status state machine and conversion tracking
- Agents: Quality score calculation (event-driven on review changes) and dashboard stats API

All modules include unit tests (14 test files, all 797 tests pass).

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

apps/api/src/app.module.ts

@@ -4,9 +4,12 @@ import { CqrsModule } from '@nestjs/cqrs';
 import { ThrottlerModule } from '@nestjs/throttler';
 import { SentryGlobalFilter, SentryModule } from '@sentry/nestjs/setup';
 import { AdminModule } from '@modules/admin';
+import { AgentsModule } from '@modules/agents';
 import { AnalyticsModule } from '@modules/analytics';
 import { AuthModule } from '@modules/auth';
 import { HealthModule } from '@modules/health';
+import { InquiriesModule } from '@modules/inquiries';
+import { LeadsModule } from '@modules/leads';
 import { ListingsModule } from '@modules/listings';
 import { McpIntegrationModule } from '@modules/mcp';
 import { HttpMetricsInterceptor, MetricsModule } from '@modules/metrics';
@@ -28,6 +31,9 @@ import { AppController } from './app.controller';
     SharedModule,
     HealthModule,
     AuthModule,
+    AgentsModule,
+    InquiriesModule,
+    LeadsModule,
     ListingsModule,
     ReviewsModule,
     SearchModule,