重构 API 为 8 领域 + 应用层架构

将后端模块拆分为 domains、applications、shared 三层，结算计算器移入 domain 纯函数目录，API 路径与测试保持不变。

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/api/src/domains/operations/audit/audit.module.ts

@@ -0,0 +1,9 @@
+import { Global, Module } from '@nestjs/common';
+import { AuditService } from './audit.service';
+
+@Global()
+@Module({
+  providers: [AuditService],
+  exports: [AuditService],
+})
+export class AuditModule {}

apps/api/src/domains/operations/audit/audit.service.ts

@@ -0,0 +1,48 @@
+import { Injectable } from '@nestjs/common';
+import { PrismaService } from '../../../shared/prisma/prisma.service';
+
+@Injectable()
+export class AuditService {
+  constructor(private prisma: PrismaService) {}
+
+  async log(data: {
+    operatorId?: bigint;
+    operatorType: string;
+    action: string;
+    module: string;
+    targetType?: string;
+    targetId?: string;
+    beforeData?: unknown;
+    afterData?: unknown;
+    ipAddress?: string;
+  }) {
+    return this.prisma.auditLog.create({
+      data: {
+        operatorId: data.operatorId,
+        operatorType: data.operatorType,
+        action: data.action,
+        module: data.module,
+        targetType: data.targetType,
+        targetId: data.targetId,
+        beforeData: data.beforeData ? JSON.stringify(data.beforeData) : null,
+        afterData: data.afterData ? JSON.stringify(data.afterData) : null,
+        ipAddress: data.ipAddress,
+      },
+    });
+  }
+
+  async list(page = 1, pageSize = 50, module?: string) {
+    const skip = (page - 1) * pageSize;
+    const where = module ? { module } : {};
+    const [items, total] = await Promise.all([
+      this.prisma.auditLog.findMany({
+        where,
+        orderBy: { createdAt: 'desc' },
+        skip,
+        take: pageSize,
+      }),
+      this.prisma.auditLog.count({ where }),
+    ]);
+    return { items, total, page, pageSize };
+  }
+}