refactor: tighten backend, flows, frontend, tests; push flows to Langflow

backend/app/flows/store.py

@@ -132,12 +132,9 @@ def validate_flow_json(flow_json: dict) -> None:
 def create_version(session: Session, flow_id: UUID, data: FlowVersionCreate) -> FlowVersion:
     get_definition(session, flow_id)
     validate_flow_json(data.langflow_json)
-    max_no = session.exec(
-        select(func.max(FlowVersion.version_no)).where(FlowVersion.flow_id == flow_id)
-    ).one()
     version = FlowVersion(
         flow_id=flow_id,
-        version_no=(max_no or 0) + 1,
+        version_no=next_version_no(session, flow_id),
         langflow_json=data.langflow_json,
         author=data.author,
         # Single choke point: sync, import, and API creation all cache the
@@ -229,6 +226,16 @@ def set_run_result(session: Session, run: FlowRun, status: str, output: dict | N
     return run
 
 
+def has_open_task(session: Session, run_id: UUID) -> bool:
+    """True when a run has an open approval task (terminal-state mapping)."""
+    return (
+        session.exec(
+            select(ApprovalTask).where(ApprovalTask.run_id == run_id, ApprovalTask.status == "open")
+        ).first()
+        is not None
+    )
+
+
 def get_run(session: Session, run_id: UUID) -> FlowRun:
     run = session.get(FlowRun, run_id)
     if run is None: