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/modules/inquiries/infrastructure/repositories/prisma-inquiry.repository.ts

@@ -0,0 +1,145 @@
+import { Injectable } from '@nestjs/common';
+import type { Inquiry as PrismaInquiry } from '@prisma/client';
+import { type PrismaService } from '@modules/shared';
+import { InquiryEntity } from '../../domain/entities/inquiry.entity';
+import type { InquiryReadDto } from '../../domain/repositories/inquiry-read.dto';
+import type { IInquiryRepository, PaginatedResult } from '../../domain/repositories/inquiry.repository';
+
+@Injectable()
+export class PrismaInquiryRepository implements IInquiryRepository {
+  constructor(private readonly prisma: PrismaService) {}
+
+  async findById(id: string): Promise<InquiryEntity | null> {
+    const inquiry = await this.prisma.inquiry.findUnique({ where: { id } });
+    return inquiry ? this.toDomain(inquiry) : null;
+  }
+
+  async save(entity: InquiryEntity): Promise<void> {
+    await this.prisma.inquiry.create({
+      data: {
+        id: entity.id,
+        listingId: entity.listingId,
+        userId: entity.userId,
+        message: entity.message,
+        phone: entity.phone,
+        isRead: entity.isRead,
+      },
+    });
+  }
+
+  async markAsRead(id: string): Promise<void> {
+    await this.prisma.inquiry.update({
+      where: { id },
+      data: { isRead: true },
+    });
+  }
+
+  async findByListing(
+    listingId: string,
+    page: number,
+    limit: number,
+  ): Promise<PaginatedResult<InquiryReadDto>> {
+    const take = Math.min(limit, 100);
+    const skip = (page - 1) * take;
+    const where = { listingId };
+
+    const [data, total] = await Promise.all([
+      this.prisma.inquiry.findMany({
+        where,
+        skip,
+        take,
+        orderBy: { createdAt: 'desc' },
+        include: {
+          listing: { select: { id: true, property: { select: { title: true } } } },
+          user: { select: { id: true, fullName: true, phone: true } },
+        },
+      }),
+      this.prisma.inquiry.count({ where }),
+    ]);
+
+    return {
+      data: data.map((r) => ({
+        id: r.id,
+        listingId: r.listingId,
+        listingTitle: r.listing.property.title,
+        userId: r.userId,
+        userName: r.user.fullName,
+        userPhone: r.user.phone,
+        message: r.message,
+        phone: r.phone,
+        isRead: r.isRead,
+        createdAt: r.createdAt.toISOString(),
+      })),
+      total,
+      page,
+      limit: take,
+      totalPages: Math.ceil(total / take),
+    };
+  }
+
+  async findByAgent(
+    agentId: string,
+    page: number,
+    limit: number,
+  ): Promise<PaginatedResult<InquiryReadDto>> {
+    const take = Math.min(limit, 100);
+    const skip = (page - 1) * take;
+    const where = { listing: { agentId } };
+
+    const [data, total] = await Promise.all([
+      this.prisma.inquiry.findMany({
+        where,
+        skip,
+        take,
+        orderBy: { createdAt: 'desc' },
+        include: {
+          listing: { select: { id: true, property: { select: { title: true } } } },
+          user: { select: { id: true, fullName: true, phone: true } },
+        },
+      }),
+      this.prisma.inquiry.count({ where }),
+    ]);
+
+    return {
+      data: data.map((r) => ({
+        id: r.id,
+        listingId: r.listingId,
+        listingTitle: r.listing.property.title,
+        userId: r.userId,
+        userName: r.user.fullName,
+        userPhone: r.user.phone,
+        message: r.message,
+        phone: r.phone,
+        isRead: r.isRead,
+        createdAt: r.createdAt.toISOString(),
+      })),
+      total,
+      page,
+      limit: take,
+      totalPages: Math.ceil(total / take),
+    };
+  }
+
+  async countUnreadByAgent(agentId: string): Promise<number> {
+    return this.prisma.inquiry.count({
+      where: {
+        isRead: false,
+        listing: { agentId },
+      },
+    });
+  }
+
+  private toDomain(raw: PrismaInquiry): InquiryEntity {
+    return new InquiryEntity(
+      raw.id,
+      {
+        listingId: raw.listingId,
+        userId: raw.userId,
+        message: raw.message,
+        phone: raw.phone,
+        isRead: raw.isRead,
+      },
+      raw.createdAt,
+    );
+  }
+}