Improvements * Sell confirmation now uses atomic pending-sale transactions with unique IDs so an item is owned by only one state at a time (inventory, pending sale, or active auction) * Confirm, cancel, inventory close, disconnect, and shutdown recovery are idempotent against double-clicks, lag, and repeated callbacks * Cancel and collect actions on existing auctions use operation locks to prevent double item returns * Failed listing validation now safely restores the item (with ground drop if the inventory is full) * Added sampled debug logging for invalid/repeated pending-sale claims (debug.pending-sales) ### Bug Fixes * Fixed item duplication when cancelling /ah sell confirmation (Cancel, GUI close, duration/category re-open, double-click, or disconnect could return the item more than once) * Pending sell items are now returned correctly on player quit and server shutdown ### Configuration * debug.pending-sales (default: false) — when true, logs every invalid/repeated pending-sale claim; when false, samples only
