feat(backend): 完善 Workflow 与 DeepResearch 的运行链路与持久化能力

功能说明：\n- 重构并增强工作流网关执行链路，支持更完整的 proposal 与 run 调度参数透传\n- 增加 DeepResearch/workflow 运行事件持久化能力并补齐建表 SQL 与查询/保存接口适配\n- 优化 lead agent 与 deep research runner 的中间态处理，增强线程收集与执行链并发控制\n- 调整工作流执行器与任务路由，提升兼容性并完善错误与回放行为\n- 补充回归测试：deep_research 持久化、workflow 并发、定义加载、引擎执行、run 流程等覆盖

offline-backend-20260512/backend/tests/test_workflow_runs.py

@@ -219,6 +219,10 @@ async def harness(monkeypatch: pytest.MonkeyPatch):
     class _Cfg:
         workflows = config
 
+        @staticmethod
+        def get_model_config(name: str):
+            return {"name": name} if name == "planner-model" else None
+
     async def _user(_request=None) -> str:
         return "user-a"
 
@@ -325,7 +329,7 @@ async def test_planning_session_selects_an_editable_candidate_then_confirms_one_
 
     created = await harness.client.post(
         f"/api/workflows/{definition['id']}/planning-sessions",
-        json={"query": "分析本周销售下滑并给出改进方案"},
+        json={"query": "分析本周销售下滑并给出改进方案", "modelName": "planner-model"},
     )
     assert created.status_code == 200, created.text
     session = created.json()
@@ -337,6 +341,10 @@ async def test_planning_session_selects_an_editable_candidate_then_confirms_one_
     ]
     assert session["proposals"][0]["title"] == "多角度调研方案"
     assert all(proposal["validation"]["valid"] for proposal in session["proposals"])
+    for proposal in session["proposals"]:
+        for node in proposal["graph"]["nodes"]:
+            if node["type"] == "agent":
+                assert node["config"]["modelName"] == "planner-model"
     parallel_graph = session["proposals"][0]["graph"]
     evidence = next(node for node in parallel_graph["nodes"] if node["type"] == "evidence_normalizer")
     synthesis = next(node for node in parallel_graph["nodes"] if node["id"] == "writer")
@@ -453,7 +461,7 @@ async def test_dedicated_workflow_controller_has_no_tools_or_thinking(
 
     response = await harness.client.post(
         f"/api/workflows/{definition['id']}/planning-sessions",
-        json={"query": "快速确认这份材料是否有缺口"},
+        json={"query": "快速确认这份材料是否有缺口", "modelName": "planner-model"},
     )
 
     assert response.status_code == 200, response.text
@@ -461,6 +469,7 @@ async def test_dedicated_workflow_controller_has_no_tools_or_thinking(
     assert captured["disable_tools"] is True
     assert captured["thinking_enabled"] is False
     assert captured["force_disable_thinking"] is True
+    assert captured["model_name"] == "planner-model"
 
 
 @pytest.mark.asyncio
@@ -505,6 +514,22 @@ async def test_planner_uses_visible_agent_catalog_when_canvas_is_only_start_and_
                 "collaborative": ["agent-research", "agent-writer"],
                 "quick_answer": ["agent-research"],
             },
+            "taskContracts": {
+                "parallel_research": {
+                    "agent-research": {
+                        "mission": "只收集新能源乘用车市场规模与增长证据。",
+                        "deliverable": "带来源和置信度的市场规模证据笔记。",
+                        "scope": "不要撰写最终报告。",
+                        "handoff": "交给策略分析师的 Evidence Pack。",
+                    },
+                    "agent-writer": {
+                        "mission": "比较 Evidence Pack 中的证据并形成判断。",
+                        "deliverable": "冲突、假设和落地建议。",
+                        "scope": "区分事实与推断。",
+                        "handoff": "交给深度研究报告写作节点。",
+                    },
+                }
+            },
             "titles": {"parallel_research": "双角色调研报告"},
         }
 
@@ -551,6 +576,13 @@ async def test_planner_uses_visible_agent_catalog_when_canvas_is_only_start_and_
         "agent-research",
         "agent-writer",
     ]
+    graph_nodes = {node["id"]: node for node in parallel["graph"]["nodes"]}
+    research_prompt = graph_nodes["__planner_agent_1__"]["config"]["promptTemplate"]
+    writer_prompt = graph_nodes["__planner_agent_3__"]["config"]["promptTemplate"]
+    assert "只收集新能源乘用车市场规模与增长证据。" in research_prompt
+    assert "不要撰写最终报告。" in research_prompt
+    assert "比较 Evidence Pack 中的证据并形成判断。" in writer_prompt
+    assert "这是工作流总控为你分配的固定岗位" in writer_prompt
     assert all(proposal["validation"]["valid"] for proposal in session["proposals"])