refactor: 优化多语言结构并新增远端语言包加载能力

1. 扁平化多语言文件层级，移除嵌套的命名空间
2. 更新组件内多语言调用路径，适配新的语言包结构
3. 重构HTTP请求错误处理逻辑
4. 新增remote-only模式的远端语言包加载器
5. 新增多语言数据源remote-only配置项

lang/en-us/components-diy/diy-category.js

@@ -1,16 +1,12 @@
 export const lang = {
-	'components-diy': {
-		diyCategory: {
-			// Expand all categories (button on the right of horizontal scroll)
-			expand: 'Expand',
-			// Click to collapse (button at the bottom of expanded popup)
-			clickToCollapse: 'Click to collapse',
-			// Scroll to bottom tip
-			reachedBottom: 'Reached the bottom~',
-			// No categories (empty state tip)
-			noCategory: 'No categories yet!',
-			// Product unit: piece
-			pieceUnit: 'pc(s)',
-		},
-	},
+	// Expand all categories (button on the right of horizontal scroll)
+	expand: 'Expand',
+	// Click to collapse (button at the bottom of expanded popup)
+	clickToCollapse: 'Click to collapse',
+	// Scroll to bottom tip
+	reachedBottom: 'Reached the bottom~',
+	// No categories (empty state tip)
+	noCategory: 'No categories yet!',
+	// Product unit: piece
+	pieceUnit: 'pc(s)',
 }

lang/en-us/components-diy/diy-index-page.js

@@ -1,14 +1,10 @@
 export const lang = {
-	'components-diy': {
-		diyIndexPage: {
-			// Home (default category name)
-			home: 'Home',
-			// Sales text: Sold X units
-			soldCount: 'Sold {count}{unit}',
-			// Sales unit: piece
-			soldUnit: 'pcs',
-			// Empty state prompt when no goods in category
-			noGoodsInCategory: 'No goods in this category',
-		},
-	},
+	// Home (default category name)
+	home: 'Home',
+	// Sales text: Sold X units
+	soldCount: 'Sold {count}{unit}',
+	// Sales unit: piece
+	soldUnit: 'pcs',
+	// Empty state prompt when no goods in category
+	noGoodsInCategory: 'No goods in this category',
 }

lang/en-us/components-diy/diy-store.js

@@ -1,14 +1,10 @@
 export const lang = {
-	'components-diy': {
-		diyStore: {
-			// Switch store button text
-			switchStore: 'Switch Store',
-			// Locating status text
-			locating: 'Locating',
-			// Getting location status text for address
-			gettingLocation: 'Getting location',
-			// Search input placeholder
-			searchPlaceholder: 'Search',
-		},
-	},
+	// Switch store button text
+	switchStore: 'Switch Store',
+	// Locating status text
+	locating: 'Locating',
+	// Getting location status text for address
+	gettingLocation: 'Getting location',
+	// Search input placeholder
+	searchPlaceholder: 'Search',
 };