fix: 恢复 language.ui 为原版 Text widget

VBox 是布局容器不支持 click 事件，导致：
- 语言代码不显示（VBox 无 otext）
- 点击无反应（VBox 不触发 click bind）
- 语言切换后代码不更新（缺少 app lang bind）

恢复为 Text widget + Popup click + lang event bind

wwwroot/i18n/language.ui

@@ -1,32 +1,13 @@
 {
 	"id":"language",
-	"widgettype":"VBox",
+	"widgettype":"Text",
 	"options":{
+		"tip":"change UI language",
+		"i18n":true,
+		"otext":"{{params_kw._lang}}",
 		"cwidth": 4,
 		"css":"clickable"
 	},
-	"subwidgets":[
-		{
-			"widgettype":"Svg",
-			"options":{
-				"url":"{{entire_url('language.svg')}}",
-				"rate":2,
-				"valign":"center",
-				"halign":"center"
-			}
-		},
-		{
-			"widgettype":"Text",
-			"id":"lang_label",
-			"options":{
-				"i18n":false,
-				"otext":"{{params_kw._lang}}",
-				"cwidth":4,
-				"css":"text-center",
-				"cfontsize":0.6
-			}
-		}
-	],
 	"binds":[
 		{
 			"wid":"self",
@@ -47,7 +28,7 @@
 			"wid":"app",
 			"event":"lang",
 			"actiontype":"script",
-			"target":"lang_label",
+			"target":"self",
 			"script":"this.set_otext(bricks.app.lang)"
 		}
 	]