Close lifecycle transition helper workplan

api/routers/workstreams.py

@@ -19,6 +19,7 @@ from api.schemas.workstream import (
     WorkstreamRead,
     WorkstreamUpdate,
 )
+from api.services.lifecycle import transition_workstream_status
 from api.workplan_status import (
     is_supported_workstream_status,
     normalize_workstream_status,
@@ -184,9 +185,13 @@ async def update_workstream(
     ws = await session.get(Workstream, workstream_id)
     if ws is None:
         raise HTTPException(status_code=404, detail="Workstream not found")
+    update_data = body.model_dump(exclude_unset=True)
+    status_update = update_data.pop("status", None)
     prev_status = ws.status
-    for field, value in body.model_dump(exclude_unset=True).items():
+    for field, value in update_data.items():
         setattr(ws, field, value)
+    if status_update is not None:
+        transition_workstream_status(ws, status_update)
     await session.commit()
     await session.refresh(ws)
 
@@ -216,7 +221,7 @@ async def archive_workstream(
     ws = await session.get(Workstream, workstream_id)
     if ws is None:
         raise HTTPException(status_code=404, detail="Workstream not found")
-    ws.status = "archived"
+    transition_workstream_status(ws, "archived")
     await session.commit()
     await session.refresh(ws)
     return ws