Add option to download missing stylesheets on startup

data/ch-s.mse-locale/locale

@@ -1,4 +1,4 @@
-mse version: 2.5.8
+mse version: 2.6.0
 installer group: Magic Set Editor/translations/chinese simplified
 full name: 简体中文 (Simplified Chinese)
 version: 2026-02-28
@@ -620,6 +620,16 @@ label:
 	stylesheet not found:
 		你要打开的套牌使用的是 "%s" 样式表
 		这个样式表在你的系统里没有找到，请选择其他方案
+	#TODO: Localize
+	searching online:					Searching online...
+	#TODO: Localize
+	searching online fail:				Not found online
+	#TODO: Localize
+	found online downloading:			Found online! Downloading...
+	#TODO: Localize
+	found online installing:			Found online! Installing...
+	#TODO: Localize
+	found online fail:					Installation failed
 
 	# preferences dialog
 	language:							语言
@@ -904,6 +914,10 @@ button:
 	upgrade group:						全部升级
 	remove group:						全部移除
 
+	# stylesheet not found dialog
+	#TODO: Localize
+	find package online:				Search Online
+
 ############################################################## Titles in the GUI
 title:
 	# window titles
@@ -1064,6 +1078,12 @@ error:
 	file not found package like:
 		没有找到文件：'%s' 在 '%s' 文件包中
 		如果你尝试从别的文件包中打开文件， 使用以下格式"/package/filename"
+	#TODO: Localize
+	file not found package like init:
+		File not found: '%s' in package '%s'
+		If this folder is empty or unused, delete it.
+	#TODO: Localize
+	package name parse error:			Unable to parse package name '%s'
 	file parse error:
 		处理文件发生错误:'%s'
 		%s