refactor: 简化 AgentScope 运行时模块与事件处理

- 移除冗余的 user_token 参数传递
- 重构 tool.result 事件使用 ToolAgentOutput 模型
- 重构 text.end 事件使用 WorkerAgentOutput 模型
- 简化 store 模块的 tool result 处理逻辑
- 更新 router/service 适配新事件结构
- 清理废弃的测试文件与设计文档
- 新增 AgentRuns 多模态存储设计文档

backend/tests/integration/v1/agent/test_sse_flow_live.py

@@ -168,8 +168,9 @@ async def test_agent_runs_events_history_live_with_image_input() -> None:
         assert "RUN_FINISHED" in event_names or "RUN_ERROR" in event_names
 
         history_resp = await client.get(
-            f"{BASE_URL}/api/v1/agent/runs/{thread_id}/history",
+            f"{BASE_URL}/api/v1/agent/history",
             headers=headers,
+            params={"threadId": thread_id},
         )
         assert history_resp.status_code == 200
         history = history_resp.json()
@@ -183,10 +184,11 @@ async def test_agent_runs_events_history_live_with_image_input() -> None:
             if isinstance(item, dict) and item.get("role") == "user"
         ]
         assert user_messages
-        attachments = user_messages[0].get("attachments")
-        assert isinstance(attachments, list)
-        assert attachments and isinstance(attachments[0], dict)
-        assert isinstance(attachments[0].get("path"), str)
+        metadata = user_messages[0].get("metadata")
+        assert isinstance(metadata, dict)
+        user_attachment = metadata.get("user_message_attachments")
+        assert isinstance(user_attachment, dict)
+        assert isinstance(user_attachment.get("path"), str)
 
     async with AsyncSessionLocal() as session:
         session_row = await session.get(AgentChatSession, UUID(thread_id))
@@ -212,7 +214,6 @@ async def test_agent_runs_events_history_live_with_image_input() -> None:
         ]
         assert user_rows
         metadata = user_rows[0].metadata_json or {}
-        attachments = metadata.get("attachments")
-        assert isinstance(attachments, list)
-        assert attachments and isinstance(attachments[0], dict)
-        assert isinstance(attachments[0].get("path"), str)
+        user_attachment = metadata.get("user_message_attachments")
+        assert isinstance(user_attachment, dict)
+        assert isinstance(user_attachment.get("path"), str)