Clarify asynchronous cleanup ownership

Signed-off-by: Loren Eteval <loren.eteval@proton.me>

Furious/Controllers/AGENTS.md

@@ -61,6 +61,10 @@ source tree's root.
   new acquisition while they remain. Final controller shutdown surfaces unresolved cleanup and preserves the
   next-start preference. Check these outcomes independently in `tests/test_controllers.py` and
   `tests/test_runtime_lifecycle.py`.
+  Pending asynchronous cleanup stays `Disconnecting`, with runtime ownership in the service. Reconnect waits for
+  successful release; a genuine cleanup failure returns to usable UI without admitting replacement resources.
+  Shutdown publishes its result only after this stop operation finishes and preserves the startup preference.
+  `tests/test_sing_tun.py` covers delayed authorization, cancellation, reconnect and shutdown with real Qt delivery.
 - System Proxy configuration is best effort. Its helper logs host failures; an explicit False return does not roll
   back an otherwise usable committed runtime or prevent Connected. Preserve exception-path recovery separately.
   Exercise actual helper results with mocked OS boundaries; Connected does not guarantee the OS proxy was applied.