feat(api): A4 数据字典与系统配置后端

背景：A4 需要字典三层合并、配置单一来源与阈值同源。\n改动：新增 catalog 模块（类型/条目/三层合并/编码不可改/快照工具）；platform 新增 SystemConfigService/Controller、NamingService 与配置版本历史；roles/users/customers/customer-fields 改为读 system_configs 上限。\n影响面：新增 13 个 REST 端点与 4 个模块注入；system_configs 写入走事务/乐观锁/版本历史；OpenAPI 快照更新。\n回滚：回滚本提交并恢复 shared 契约；新增表可保留。\n验证：api typecheck/build；单测 137；集成 58；OpenAPI diff 无破坏性变更。

apps/api/src/modules/client/customer-fields.service.ts

@@ -18,6 +18,7 @@ import type { ScopeContext } from '../../common/security/scope/scope-context';
 import { isCustomerVisible, requireScopeContext } from '../../common/security/scope/scope-context';
 import type { PrismaService } from '../../infra/prisma/prisma.service';
 import { PRISMA } from '../../infra/tokens';
+import { SystemConfigService } from '../platform/system-config/system-config.service';
 import { type CustomerFieldRow, toCustomerField } from './client.mapper';
 
 const FIELD_INCLUDE = {
@@ -51,7 +52,10 @@ function industryPath(customer: {
  */
 @Injectable()
 export class CustomerFieldsService {
-  constructor(@Inject(PRISMA) private readonly prisma: PrismaService) {}
+  constructor(
+    @Inject(PRISMA) private readonly prisma: PrismaService,
+    @Inject(SystemConfigService) private readonly systemConfig: SystemConfigService,
+  ) {}
 
   async list(
     query: CustomerFieldListQuery,
@@ -147,12 +151,7 @@ export class CustomerFieldsService {
     }
     if (input.entersGeneration) {
       const used = await this.genUsedCount(customerId);
-      if (used >= CUSTOMER_GEN_FIELD_LIMIT) {
-        throw new AppException({
-          code: ErrorCode.PARAM_INVALID,
-          message: `进入生成字段已达 ${CUSTOMER_GEN_FIELD_LIMIT} 个上限，请先停用或驳回其他字段`,
-        });
-      }
+      await this.assertGenFieldLimit(used);
     }
     const id = ulid();
     await this.prisma.customerField.create({
@@ -200,12 +199,7 @@ export class CustomerFieldsService {
     }
     if (input.decision === 'approve' && existing.entersGeneration) {
       const used = await this.genUsedCount(existing.customerId, id);
-      if (used >= CUSTOMER_GEN_FIELD_LIMIT) {
-        throw new AppException({
-          code: ErrorCode.PARAM_INVALID,
-          message: `进入生成字段已达 ${CUSTOMER_GEN_FIELD_LIMIT} 个上限，审批后仍超限`,
-        });
-      }
+      await this.assertGenFieldLimit(used, '审批后仍超限');
     }
     await this.prisma.customerField.update({
       where: { id },
@@ -231,6 +225,20 @@ export class CustomerFieldsService {
     return toCustomerField(row);
   }
 
+  /** 进入生成字段上限读 system_configs（R-26）；shared 常量仅作读失败兜底（默认 5） */
+  private async assertGenFieldLimit(used: number, hint = '请先停用或驳回其他字段'): Promise<void> {
+    const limit = await this.systemConfig.getNumber(
+      'limit.customer.gen_field',
+      CUSTOMER_GEN_FIELD_LIMIT,
+    );
+    if (used >= limit) {
+      throw new AppException({
+        code: ErrorCode.PARAM_INVALID,
+        message: `进入生成字段已达 ${String(limit)} 个上限，${hint}`,
+      });
+    }
+  }
+
   private async genUsedCount(customerId: string, excludeId?: string): Promise<number> {
     return this.prisma.customerField.count({
       where: {

apps/api/src/modules/client/customers.service.ts

@@ -22,6 +22,7 @@ import type { ScopeContext } from '../../common/security/scope/scope-context';
 import { isCustomerVisible, requireScopeContext } from '../../common/security/scope/scope-context';
 import type { PrismaService } from '../../infra/prisma/prisma.service';
 import { PRISMA } from '../../infra/tokens';
+import { SystemConfigService } from '../platform/system-config/system-config.service';
 import { type CustomerSummaryRow, toCustomerDetail, toCustomerSummary } from './client.mapper';
 import { IndustriesService } from './industries.service';
 
@@ -61,6 +62,7 @@ export class CustomersService {
   constructor(
     @Inject(PRISMA) private readonly prisma: PrismaService,
     @Inject(IndustriesService) private readonly industries: IndustriesService,
+    @Inject(SystemConfigService) private readonly systemConfig: SystemConfigService,
   ) {}
 
   async list(
@@ -126,7 +128,7 @@ export class CustomersService {
     await this.industries.assertLeafIndustry(input.industryId);
     await this.ensureOwner(input.ownerUserId);
     const baseFields = input.baseFields ?? [];
-    this.assertBaseFieldLimit(baseFields.length);
+    await this.assertBaseFieldLimit(baseFields.length);
     const id = ulid();
     try {
       await this.prisma.customer.create({
@@ -184,7 +186,7 @@ export class CustomersService {
     if (input.ownerUserId !== undefined && input.ownerUserId !== existing.ownerUserId) {
       await this.ensureOwner(input.ownerUserId);
     }
-    if (input.baseFields !== undefined) this.assertBaseFieldLimit(input.baseFields.length);
+    if (input.baseFields !== undefined) await this.assertBaseFieldLimit(input.baseFields.length);
     if (input.name !== undefined && input.name !== existing.name) {
       const duplicate = await this.prisma.customer.findFirst({
         where: {
@@ -377,11 +379,16 @@ export class CustomersService {
     }
   }
 
-  private assertBaseFieldLimit(count: number): void {
-    if (count > CUSTOMER_BASE_FIELD_LIMIT) {
+  /** 基础字段上限读 system_configs（R-26）；shared 常量仅作读失败兜底（默认 10） */
+  private async assertBaseFieldLimit(count: number): Promise<void> {
+    const limit = await this.systemConfig.getNumber(
+      'limit.customer.base_field',
+      CUSTOMER_BASE_FIELD_LIMIT,
+    );
+    if (count > limit) {
       throw new AppException({
         code: ErrorCode.PARAM_INVALID,
-        message: `基础字段最多 ${CUSTOMER_BASE_FIELD_LIMIT} 个，当前 ${count} 个`,
+        message: `基础字段最多 ${String(limit)} 个，当前 ${String(count)} 个`,
       });
     }
   }