fix(cr): set stage='review' on submit so demo-generated CRs route through the new review form (#920 round-2 follow-up)

Author: emjay0921

spp_change_request_v2/models/change_request.py

@@ -1018,6 +1018,7 @@ def _on_submit(self):
         action = "resubmitted" if old_state == "revision" else "submitted"
         self._create_audit_event("submitted", old_state, "pending")
         self._create_log(action)
+        self.stage = "review"
 
     def _on_request_revision(self, notes):
         super()._on_request_revision(notes)