Nothing drained AppState's movie_commands mpsc, so manual search and
one-click grab were accepted with 202 and then did nothing until the
64-slot buffer filled and the endpoint started 503ing.
A new daemon task drains it: Search resets the movie's backoff and
runs the targeted-search + grab lane immediately; Grab sends the
already-chosen release straight to Transmission.
Closes#107
Miguel Palhas