Used-hardware dealer customer and GPU appraisal registration

A scav-type seller visits now and then with three to five used cards. An
honest dealer sells at true value, a middleman adds 8%, a scammer mixes in
fakes (relabelled cheap chips) priced at 90% of the labelled model's value.
The markup is a client-temporary item feature, so a bought card is only
worth its real value. Cards are registered as appraisal items; the correct
value is the same function as the sale value.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/Decentralized/ModEntry.cs

@@ -15,6 +15,7 @@ namespace Decentralized
             Unlock.Register();
             Night.Subscribe();
             DealerStock.Subscribe();
+            UsedDealerClient.Subscribe();
             ModHook.OnGameLoadedLate += Session.Load;
             ModHook.OnNewGameStarted += OnNewGame;
             Log.Info($"{ModInfo.Name} {ModInfo.Version} 已启用");
@@ -25,6 +26,7 @@ namespace Decentralized
             Items.Unsubscribe();
             Night.Unsubscribe();
             DealerStock.Unsubscribe();
+            UsedDealerClient.Unsubscribe();
             ModHook.OnGameLoadedLate -= Session.Load;
             ModHook.OnNewGameStarted -= OnNewGame;
         }