Studio: address Deep Research lifecycle review

studio/backend/core/research_runs.py

@@ -385,6 +385,8 @@ class ResearchSupervisor:
         self._stopping.set()
         try:
             if self._task is not None:
+                for cancel_event in self._cancel_events.values():
+                    cancel_event.set()
                 self._task.cancel()
                 try:
                     await self._task

studio/backend/storage/research_runs_db.py

@@ -865,6 +865,7 @@ def reset_execution_steps(run_id: str, worker_id: str | None = None) -> bool:
             conn.commit()
             return False
         conn.execute("DELETE FROM research_plan_steps WHERE run_id = ?", (run_id,))
+        conn.execute("DELETE FROM research_sources WHERE run_id = ?", (run_id,))
         conn.commit()
         return True
     except Exception:

studio/backend/tests/test_research_runs_storage.py

@@ -448,6 +448,43 @@ def test_recovery_releases_expired_leases(research_home, status):
     assert claimed["status"] == expected
 
 
+def test_execution_reset_clears_steps_and_sources(research_home):
+    _create()
+    plan = research_db.set_plan("run-1", _plan())
+    research_db.approve("run-1", plan["planRevision"], plan["planHash"])
+    research_db.claim_next("worker-1")
+    research_db.upsert_execution_step(
+        "run-1", 0, "Old step", "old query", "completed", worker_id = "worker-1"
+    )
+    research_db.upsert_source("run-1", 0, "https://old.example", "Old", "Stale", "worker-1")
+
+    assert research_db.reset_execution_steps("run-1", "worker-1") is True
+    run = research_db.get_run("run-1")
+    assert run["steps"] == []
+    assert run["sources"] == []
+
+
+def test_supervisor_stop_signals_tool_cancellation_before_task_cancelled(research_home):
+    from core.research_runs import ResearchSupervisor
+    async def scenario():
+        supervisor = ResearchSupervisor(SimpleNamespace(state = SimpleNamespace()))
+        cancel_event = supervisor._cancel_event("run-1")
+
+        async def active_run():
+            try:
+                await asyncio.Event().wait()
+            except asyncio.CancelledError:
+                assert cancel_event.is_set()
+                raise
+
+        supervisor._task = asyncio.create_task(active_run())
+        await asyncio.sleep(0)
+        await supervisor.stop()
+        assert cancel_event.is_set()
+
+    asyncio.run(scenario())
+
+
 def test_sources_are_normalized_by_url(research_home):
     _create()
     research_db.upsert_source("run-1", 0, "https://example.com/a", "Old", "one")

studio/frontend/src/features/chat/api/chat-adapter.ts

@@ -2036,7 +2036,9 @@ export function createOpenAIStreamAdapter(
                    autoinject_min_score: runtime.ragAutoInjectMinScore,
                 }
               : {
-                  thread_id: resolvedThreadId,
+                  ...(runtime.ragEnabled
+                    ? { thread_id: resolvedThreadId }
+                    : {}),
                   ...(researchProjectId
                     ? { project_id: researchProjectId }
                     : {}),

tests/studio/test_deep_research_frontend_contract.py

@@ -59,6 +59,7 @@ def test_research_mode_is_single_chat_and_detaches_without_cancel() -> None:
     assert "signal: researchFollowController.signal" in adapter
     assert "beginExternalResearchFollow(" in adapter
     assert "ragScope" in adapter
+    assert "runtime.ragEnabled\n                    ? { thread_id: resolvedThreadId }" in adapter
     create_block = adapter.split("createdRun = await createResearchRun({", 1)[1].split("});", 1)[0]
     assert "modelId:" not in create_block
     assert "prompt," not in create_block