fix item ID sync bug with Challenge grave recovery items

src/CommandFormats.hh

@@ -5818,7 +5818,7 @@ struct G_BattleModeLevelUp_BB_6xD0 {
 struct G_ChallengeModeGraveRecoveryItemRequest_BB_6xD1 {
   G_ClientIDHeader header;
   le_uint16_t floor = 0;
-  le_uint16_t unknown_a2 = 0;
+  le_uint16_t unknown_a1 = 0;
   le_float x = 0;
   le_float z = 0;
   le_uint32_t item_type = 0; // Should be < 6

src/ReceiveSubcommands.cc

@@ -3059,7 +3059,7 @@ static void on_request_challenge_grave_recovery_item_bb(shared_ptr<Client> c, ui
         ItemData(0x0301020000010000), // Trifluid x1
     };
     ItemData item = items.at(cmd.item_type);
-    item.id = l->generate_item_id(0xFF);
+    item.id = l->generate_item_id(cmd.header.client_id);
     l->add_item(cmd.floor, item, cmd.x, cmd.z, 0x00F);
     send_drop_stacked_item_to_lobby(l, item, cmd.floor, cmd.x, cmd.z);
   }