refactor: make model sessions explicit

tests/test_agent_task_runs.py

@@ -10,11 +10,11 @@ from sqlalchemy.exc import IntegrityError
 from app.agent.orchestrator import AgentManager
 from app.agent.tools.impl.query_agent_tasks import QueryAgentTasksTool
 from app.db.engine import get_engine
+from app.db import base as db_base
 from app.db.oper.agenttask import AgentTaskOper
 from app.db.models.agenttask import AgentTask
 from app.db.models.agenttaskrun import AgentTaskRun
 from app.db.session import SessionFactory
-from app.db import decorators
 
 
 Engine = get_engine()
@@ -141,9 +141,11 @@ def test_agenttaskrun_oper_reuses_explicit_query_session(db, monkeypatch):
     run = AgentTaskOper().begin_run(task.id)
     assert run
     monkeypatch.setattr(
-        decorators,
-        "ScopedSession",
-        lambda: (_ for _ in ()).throw(AssertionError("不应创建额外同步会话")),
+        db_base,
+        "run_sync_transaction",
+        lambda _operation: (_ for _ in ()).throw(
+            AssertionError("不应创建额外同步事务")
+        ),
     )
 
     oper = AgentTaskOper(db.session)
@@ -151,19 +153,6 @@ def test_agenttaskrun_oper_reuses_explicit_query_session(db, monkeypatch):
     assert oper.list_runs(task.id)
 
 
-def test_agenttaskrun_model_legacy_query_keeps_keyword_abi(monkeypatch):
-    """旧插件以关键字直调 AgentTaskRun 时仍自动补入短会话。"""
-    opened = []
-    monkeypatch.setattr(
-        decorators,
-        "ScopedSession",
-        lambda: (opened.append(True) or SessionFactory()),
-    )
-
-    assert AgentTaskRun.get_by_run_id(run_id="missing-legacy") is None
-    assert opened == [True]
-
-
 def test_begin_run_rolls_back_task_claim_when_run_insert_fails() -> None:
     """运行记录插入失败时，任务的 running 投影必须随事务回滚。"""
     first_task = _add_task("run-rollback-first")