feat(agent-core): 增加智能编排与模型工具基础

agent_core/structured_output.py

@@ -0,0 +1,8 @@
+def build_mock_structured_output(output_type: str, user_input: str, references: list) -> dict:
+    return {
+        "output_type": output_type,
+        "summary": f"模拟结构化输出：{user_input}",
+        "references_count": len(references),
+        "risk_level": "low",
+        "suggested_actions": ["补充真实 LLM Provider 后替换模拟结果"],
+    }