Localization Helper

在Leavn应用中查找硬编码的字符串，添加I18n.str()调用，并为所有6种支持的语言（en, es, de, zh-Hans, ar, he）创建本地化键。

Replace hardcoded Text() strings with I18n pattern for 6 languages.

Pattern:

// BEFORE
Text("Verse of the Day")

// AFTER
Text(I18n.str("widget.verseOfDay", default: "Verse of the Day"))

Add keys to: LeavnApp/Sources/Resources/{lang}.lproj/Localizable.strings

Use when: Hardcoded strings found, adding UI text, widget/ChatterboxKit localization