chore: change draft var to user scoped (#33066)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: QuantumGhost <obelisk.reg+git@gmail.com>

api/tests/unit_tests/services/workflow/test_draft_var_loader_simple.py

@@ -24,7 +24,11 @@ class TestDraftVarLoaderSimple:
     def draft_var_loader(self, mock_engine):
         """Create DraftVarLoader instance for testing."""
         return DraftVarLoader(
-            engine=mock_engine, app_id="test-app-id", tenant_id="test-tenant-id", fallback_variables=[]
+            engine=mock_engine,
+            app_id="test-app-id",
+            tenant_id="test-tenant-id",
+            user_id="test-user-id",
+            fallback_variables=[],
         )
 
     def test_load_offloaded_variable_string_type_unit(self, draft_var_loader):
@@ -323,7 +327,9 @@ class TestDraftVarLoaderSimple:
 
                                     # Verify service method was called
                                     mock_service.get_draft_variables_by_selectors.assert_called_once_with(
-                                        draft_var_loader._app_id, selectors
+                                        draft_var_loader._app_id,
+                                        selectors,
+                                        user_id=draft_var_loader._user_id,
                                     )
 
                                     # Verify offloaded variable loading was called

api/tests/unit_tests/services/workflow/test_workflow_draft_variable_service.py

@@ -8,7 +8,7 @@ from sqlalchemy import Engine
 from sqlalchemy.orm import Session
 
 from dify_graph.constants import SYSTEM_VARIABLE_NODE_ID
-from dify_graph.enums import BuiltinNodeTypes
+from dify_graph.enums import BuiltinNodeTypes, SystemVariableKey
 from dify_graph.variables.segments import StringSegment
 from dify_graph.variables.types import SegmentType
 from libs.uuid_utils import uuidv7
@@ -182,6 +182,42 @@ class TestDraftVariableSaver:
         draft_vars = mock_batch_upsert.call_args[0][1]
         assert len(draft_vars) == 2
 
+    @patch("services.workflow_draft_variable_service._batch_upsert_draft_variable", autospec=True)
+    def test_start_node_save_persists_sys_timestamp_and_workflow_run_id(self, mock_batch_upsert):
+        """Start node should persist common `sys.*` variables, not only `sys.files`."""
+        mock_session = MagicMock(spec=Session)
+        mock_user = MagicMock(spec=Account)
+        mock_user.id = "test-user-id"
+        mock_user.tenant_id = "test-tenant-id"
+
+        saver = DraftVariableSaver(
+            session=mock_session,
+            app_id="test-app-id",
+            node_id="start-node-id",
+            node_type=BuiltinNodeTypes.START,
+            node_execution_id="exec-id",
+            user=mock_user,
+        )
+
+        outputs = {
+            f"{SYSTEM_VARIABLE_NODE_ID}.{SystemVariableKey.TIMESTAMP}": 1700000000,
+            f"{SYSTEM_VARIABLE_NODE_ID}.{SystemVariableKey.WORKFLOW_EXECUTION_ID}": "run-id-123",
+        }
+
+        saver.save(outputs=outputs)
+
+        mock_batch_upsert.assert_called_once()
+        draft_vars = mock_batch_upsert.call_args[0][1]
+
+        # plus one dummy output because there are no non-sys Start inputs
+        assert len(draft_vars) == 3
+
+        sys_vars = [v for v in draft_vars if v.node_id == SYSTEM_VARIABLE_NODE_ID]
+        assert {v.name for v in sys_vars} == {
+            str(SystemVariableKey.TIMESTAMP),
+            str(SystemVariableKey.WORKFLOW_EXECUTION_ID),
+        }
+
 
 class TestWorkflowDraftVariableService:
     def _get_test_app_id(self):

api/tests/unit_tests/services/workflow/test_workflow_service.py

@@ -245,6 +245,7 @@ class TestWorkflowService:
             workflow=workflow,
             node_config=node_config,
             manual_inputs={"#node-0.result#": "LLM output"},
+            user_id="account-1",
         )
 
         node.render_form_content_with_outputs.assert_called_once()