refactor: 下沉 Word 导出执行链到 chat 服务层

apps/chat/services.py

@@ -70,6 +70,51 @@ def execute_conversation_agent(
     return result, audit_log
 
 
+def execute_conversation_export(*, batch, conversation: Conversation) -> dict:
+    """
+    在服务层串起 Word 导出、会话摘要更新和审计留痕。
+
+    View 只负责提示成功/失败消息，不直接承载导出编排细节。
+    """
+    from .export_service import (
+        generate_registration_export,
+        update_conversation_with_export_report,
+    )
+
+    upstream_summary = (
+        (conversation.latest_summary or {}).get("upstream_structured_output")
+        or (conversation.latest_summary or {}).get("structured_output")
+        or {}
+    )
+    export_report = generate_registration_export(
+        batch=batch,
+        conversation=conversation,
+        upstream_summary=upstream_summary,
+    )
+    update_conversation_with_export_report(conversation, export_report)
+    audit_log = create_audit_log(
+        "document_review",
+        "Word 回填导出",
+        "生成 Word 导出文件",
+        AgentResult(
+            answer=export_report.get("summary", ""),
+            structured_output=export_report,
+            status="success",
+            conversation_id=conversation.conversation_id,
+            batch_id=conversation.batch_id,
+            product_name=conversation.product_name,
+            node_results=conversation.node_results,
+        ),
+        batch_id=conversation.batch_id,
+        conversation_id=conversation.conversation_id,
+        product_name=conversation.product_name,
+    )
+    return {
+        "export_report": export_report,
+        "audit_log": audit_log,
+    }
+
+
 def _generate_conversation_id() -> str:
     return f"conv-{Conversation.objects.count() + 1:03d}"