fix: auction house refresh failed after browse-all (empty name search)

The auto-refresh after successful bid/buyout was gated on
lastAuctionSearch_.name.length() > 0, so a browse-all search (empty
name) would never refresh. Replaced with a hasAuctionSearch_ flag
that's set on any search regardless of the name filter.

include/game/inventory_handler.hpp

@@ -374,6 +374,7 @@ private:
         uint32_t offset = 0;
     };
     AuctionSearchParams lastAuctionSearch_;
+    bool hasAuctionSearch_ = false;  // true after any search (including empty-name browse-all)
     enum class AuctionResultTarget { BROWSE, OWNER, BIDDER };
     AuctionResultTarget pendingAuctionTarget_ = AuctionResultTarget::BROWSE;