- A cache-hit search aborts any older in-flight stock_search and clears loading; StockPhotoTab only applies the newest request's result - A bare 404 means 'stock unavailable' only for the stock_search probe; on stock_import it is an ordinary error (an explicit invalid/unknown action error still disables the tab) Refs #55 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>