The priority arrows changed one step per click, so setting a large value meant many clicks. Now a
press-and-hold auto-repeats at an accelerating rate (a quick tap still steps once; keyboard path
kept), and the PATCH is debounced per channel so a hold sends one request with the final value, not
one per notch (flushed on unmount). The value also sits LEFT of the arrows (cursor never covers it)
and is click-to-edit — type any integer directly, negatives allowed — via an absolutely-positioned
input that overlays without disturbing the table row layout.