fix(ai): 修复 Nest DI 启动失败

- A2uiSubmissionsService/DataSource/BusinessContextService 等构造参数
  由 import type 改为值导入，确保 Nest 能解析依赖
- 验证：dev 模式后端正常启动，相关 243 个测试通过

apps/server/src/agent-context/get-business-context.tool.ts

@@ -1,7 +1,7 @@
 import { Injectable } from '@nestjs/common';
 import type { AgentToolContext, ToolDef, ToolInputResult } from '../agent-tools/agent-tool.types';
 import { rejectUnknownKeys, optionalString } from '../agent-tools/tools/tool-input';
-import type { BusinessContextService } from './business-context.service';
+import { BusinessContextService } from './business-context.service';
 
 interface GetBusinessContextInput {
   workflowKey?: string;