feat: AG-UI 协议对齐与路由导航功能

- 前端: 添加 SSE 流式支持、stateSnapshot 事件、路由导航工具
- 前端: 实现工具调用审批流程，支持 pending 状态展示
- 后端: Agent 状态管理与会话持久化相关重构
- 文档: 新增 agent-agui-full-alignance 设计文档
- 测试: 补充相关单元测试和集成测试

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

@@ -2,7 +2,7 @@ from __future__ import annotations
 
 import os
 from datetime import datetime, timedelta, timezone
-from uuid import UUID
+from uuid import UUID, uuid4
 
 import httpx
 import jwt
@@ -56,15 +56,25 @@ async def test_agent_sse_closed_loop_live() -> None:
         run_resp = await client.post(
             f"{BASE_URL}/api/v1/agent/runs",
             headers=headers,
-            json={"prompt": "请用一句话介绍你自己"},
+            json={
+                "threadId": str(uuid4()),
+                "runId": "run-live-1",
+                "state": {},
+                "messages": [
+                    {"id": "u1", "role": "user", "content": "请用一句话介绍你自己"}
+                ],
+                "tools": [],
+                "context": [],
+                "forwardedProps": {},
+            },
         )
         assert run_resp.status_code == 202
 
         accepted = run_resp.json()
-        session_id = str(accepted["session_id"])
-        assert session_id
+        thread_id = str(accepted["threadId"])
+        assert thread_id
 
-        events_url = f"{BASE_URL}/api/v1/agent/runs/{session_id}/events"
+        events_url = f"{BASE_URL}/api/v1/agent/runs/{thread_id}/events"
         event_names: list[str] = []
         async with client.stream("GET", events_url, headers=headers, timeout=20.0) as sse_resp:
             assert sse_resp.status_code == 200
@@ -77,13 +87,13 @@ async def test_agent_sse_closed_loop_live() -> None:
         assert "RUN_FINISHED" in event_names or "RUN_ERROR" in event_names
 
     async with AsyncSessionLocal() as session:
-        session_row = await session.get(AgentChatSession, UUID(session_id))
+        session_row = await session.get(AgentChatSession, UUID(thread_id))
         assert session_row is not None
         assert session_row.message_count >= 1
         assert session_row.total_tokens >= 0
         assert session_row.total_cost >= 0
 
         rows = await session.execute(
-            select(AgentChatMessage).where(AgentChatMessage.session_id == UUID(session_id))
+            select(AgentChatMessage).where(AgentChatMessage.session_id == UUID(thread_id))
         )
         assert len(list(rows.scalars().all())) >= 1