Add compact accessible client summaries and menu discounts in percent or rubles with explicit durations. Preserve ordinary catalog prices and order line snapshots; derive current prices and expire promotions automatically without background writes. Keep fractional prices, legacy sale compatibility, and regression coverage. Full pull-request QA passed. Publication remains gated by full main QA and byte-for-byte production asset and UI verification.
setupOldButton() polled the DOM every 4s forever after the menu editor
first opened, with no way to ever stop - the interval id was not even
kept in a variable. It now returns whether the button was found, the
interval only starts when the first attempt fails, and clears itself
on the first successful attempt (also wired into the existing
disconnect() cleanup alongside the other timers).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
