Easy Gen had no way to stop a run — the only exit was the ComfyUI queue. Adds
the same "■ Interrupt" control the Cutting Room's player readout uses (shared
.gen-interrupt styling), living inside the progress panel so it exists only
while there is something to stop.
ComfyUI records an interrupted prompt in history as status_str "error" with no
media, which the status endpoint cannot tell apart from a real crash — so watch()
remembers that the stop was asked for and reports "Generation stopped." instead
of "Generation failed.", while still showing any partial media the run wrote.
A failed interrupt call re-enables the button and says so rather than leaving a
dead control over a run that is still going.
Co-Authored-By: Claude <noreply@anthropic.com>
