feat(ai): 业务上下文感知与 A2UI 链路统一

- 新增代码内业务上下文元数据层（实体字典 + 三大闭环工作流）
- 新增 get_business_context / get_entity_schema / get_pending_tasks 运行时工具
- SYSTEM_PROMPT 与技能目录改为先查业务流程/待办再执行
- A2UI 增加 ai_a2ui_submissions 幂等表、表单过期、ui.artifact 事件
- 提交回灌携带 submissionId / fieldErrors / 下一步建议
- 前端 uiArtifacts 归一化与过期表单禁用

apps/server/src/ai-chat/ai-chat.tool-actions.import.ts

@@ -8,6 +8,7 @@ import { permittedStepKeys } from '../imports/imports.access';
 import { expandStageSheets } from '../imports/imports.mapping';
 import type { AiChatServiceContext, AiSseEmitter, ModelToolCall } from './ai-chat.types';
 import type { AgentToolContext } from './ai-chat.tools';
+import { buildA2uiArtifact } from './ai-a2ui.artifact';
 import { AiMessage } from './entities';
 import { finishToolRun, startToolRun } from './ai-chat.tools';
 import {
@@ -155,6 +156,17 @@ export const executePreflightImport = makeImportToolExecutor(
         .join('、') || '未识别到可导入阶段'}`,
     }, emit);
     emit('ui.import_preflight', { messageId, preflight: preflightCard });
+    emit('ui.artifact', {
+      messageId,
+      artifact: buildA2uiArtifact({
+        type: 'import_preflight',
+        id: `preflight-${attachment.id}`,
+        status: 'pending',
+        messageId,
+        conversationId: assistant.conversationId,
+        payload: preflightCard,
+      }),
+    });
     return preflightModelPayload(preflight, permittedSteps);
   });
 
@@ -241,6 +253,17 @@ export const executeStartImportWizard = makeImportToolExecutor(
       });
     }
     emit('ui.import_wizard', { messageId, wizard });
+    emit('ui.artifact', {
+      messageId,
+      artifact: buildA2uiArtifact({
+        type: 'import_wizard',
+        id: `wizard-${detail.id}`,
+        status: 'pending',
+        messageId,
+        conversationId: assistant.conversationId,
+        payload: wizard,
+      }),
+    });
     return JSON.stringify({
       status: 'success',
       runId: detail.id,