Fix double-click required to stop Redis queue workflows

Don't clear the .job_id file immediately after calling cancel_job().
This allows get_workflow_status() to see the "canceled" state and
correctly report the workflow as stopped. Previously, clearing the
file caused a fallback to PID checking, which showed "running" if
commands were still executing.

https://claude.ai/code/session_013VFNJ1Sznugpony3r2Mgxt

Author: claude

src/workflow/WorkflowManager.py

@@ -184,7 +184,8 @@ def stop_workflow(self) -> bool:
             if job_id:
                 success = self._queue_manager.cancel_job(job_id)
                 if success:
-                    self._queue_manager.clear_job_id(self.workflow_dir)
+                    # Don't clear job_id here - let get_workflow_status() see the
+                    # "canceled" state. The file is cleaned up when the job expires.
                     return True
 
         # Fallback: stop local process