feat(item): 添加三阶魔器宝箱及其相关配置

- 在 dropgroup.config 中添加了新的掉落组配置（ID 100881）
- 在 droptable.config 中添加了新的掉落表配置（ID 2100188）
- 在 StdItems.config 中添加了三阶魔器宝箱的物品配置（ID 1394）

LogicServer/data/config/drop/droptable.config

@@ -10347,4 +10347,19 @@ DropTableConfig = {
 		},
 		weeklimit = {},
 	},
+	[2100188] = {
+		id = 2100188,
+		type = 2,
+		table = {
+			{ rate = 100, type = 0, id = 965, count = 1 },
+			{ rate = 100, type = 0, id = 966, count = 1 },
+			{ rate = 100, type = 0, id = 967, count = 1 },
+			{ rate = 100, type = 0, id = 968, count = 1 },
+			{ rate = 100, type = 0, id = 969, count = 1 },
+			{ rate = 100, type = 0, id = 988, count = 1 },
+			{ rate = 100, type = 0, id = 981, count = 1 },
+			{ rate = 100, type = 0, id = 980, count = 1 },
+		},
+		weeklimit = {},
+	},
 }