feat: 完善 HomeView 国际化支持

- 新增 LanguageManager 支持应用内语言切换
- 新增 Localizable.xcstrings 包含 78 个翻译键
- 修复 HomeView 硬编码文本，改用 String(localized:)
- 支持简体中文、繁体中文、英文三种语言

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

to-live-photo/to-live-photo/LanguageManager.swift

@@ -0,0 +1,88 @@
+import SwiftUI
+
+/// 语言管理器：支持应用内动态切换语言
+@Observable
+final class LanguageManager {
+    
+    /// 支持的语言
+    enum Language: String, CaseIterable, Identifiable {
+        case system = "system"
+        case zhHans = "zh-Hans"
+        case zhHant = "zh-Hant"
+        case en = "en"
+        
+        var id: String { rawValue }
+        
+        var displayName: String {
+            switch self {
+            case .system: return "跟随系统"
+            case .zhHans: return "简体中文"
+            case .zhHant: return "繁體中文"
+            case .en: return "English"
+            }
+        }
+        
+        var locale: Locale? {
+            switch self {
+            case .system: return nil
+            case .zhHans: return Locale(identifier: "zh-Hans")
+            case .zhHant: return Locale(identifier: "zh-Hant")
+            case .en: return Locale(identifier: "en")
+            }
+        }
+    }
+    
+    /// 单例
+    static let shared = LanguageManager()
+    
+    /// 当前选择的语言
+    var current: Language {
+        didSet {
+            UserDefaults.standard.set(current.rawValue, forKey: "app_language")
+            applyLanguage()
+        }
+    }
+    
+    /// 可用语言列表
+    var availableLanguages: [Language] {
+        Language.allCases
+    }
+    
+    private init() {
+        let savedLanguage = UserDefaults.standard.string(forKey: "app_language") ?? "system"
+        self.current = Language(rawValue: savedLanguage) ?? .system
+        applyLanguage()
+    }
+    
+    /// 应用语言设置
+    private func applyLanguage() {
+        if current == .system {
+            UserDefaults.standard.removeObject(forKey: "AppleLanguages")
+        } else {
+            UserDefaults.standard.set([current.rawValue], forKey: "AppleLanguages")
+        }
+        UserDefaults.standard.synchronize()
+    }
+    
+    /// 获取本地化字符串
+    func localizedString(_ key: String) -> String {
+        if current == .system {
+            return String(localized: String.LocalizationValue(key))
+        }
+        
+        guard let path = Bundle.main.path(forResource: current.rawValue, ofType: "lproj"),
+              let bundle = Bundle(path: path) else {
+            return String(localized: String.LocalizationValue(key))
+        }
+        
+        return NSLocalizedString(key, bundle: bundle, comment: "")
+    }
+}
+
+// MARK: - 便捷扩展
+extension String {
+    /// 本地化字符串
+    var localized: String {
+        LanguageManager.shared.localizedString(self)
+    }
+}

to-live-photo/to-live-photo/Views/HomeView.swift

@@ -71,11 +71,11 @@ struct HomeView: View {
                 }
 
                 VStack(spacing: DesignTokens.Spacing.sm) {
-                    Text("Live Photo 制作")
+                    Text(String(localized: "home.title"))
                         .font(.system(size: DesignTokens.FontSize.xxl, weight: .bold))
                         .foregroundColor(.textPrimary)
 
-                    Text("选择视频，一键转换为动态壁纸")
+                    Text(String(localized: "home.subtitle"))
                         .font(.system(size: DesignTokens.FontSize.base))
                         .foregroundColor(.textSecondary)
                         .multilineTextAlignment(.center)
@@ -90,7 +90,7 @@ struct HomeView: View {
                     HStack(spacing: DesignTokens.Spacing.sm) {
                         Image(systemName: "video.badge.plus")
                             .font(.system(size: 18, weight: .semibold))
-                        Text("选择视频")
+                        Text(String(localized: "home.selectVideo"))
                             .font(.system(size: DesignTokens.FontSize.base, weight: .semibold))
                     }
                     .foregroundColor(.white)
@@ -111,7 +111,7 @@ struct HomeView: View {
                     HStack(spacing: DesignTokens.Spacing.sm) {
                         ProgressView()
                             .tint(.accentPurple)
-                        Text("正在加载视频...")
+                        Text(String(localized: "home.loading"))
                             .font(.system(size: DesignTokens.FontSize.sm))
                             .foregroundColor(.textSecondary)
                     }
@@ -149,7 +149,7 @@ struct HomeView: View {
                             .foregroundColor(.accentOrange)
                     }
 
-                    Text("快速上手")
+                    Text(String(localized: "home.quickStart"))
                         .font(.system(size: DesignTokens.FontSize.lg, weight: .semibold))
                         .foregroundColor(.textPrimary)
 
@@ -157,15 +157,15 @@ struct HomeView: View {
                 }
 
                 VStack(alignment: .leading, spacing: DesignTokens.Spacing.md) {
-                    QuickStartStep(number: 1, text: "点击上方「选择视频」导入素材", color: .accentPurple)
-                    QuickStartStep(number: 2, text: "调整比例和时长，选择封面帧", color: .accentCyan)
-                    QuickStartStep(number: 3, text: "开启 AI 增强提升画质（可选）", color: .accentPink)
-                    QuickStartStep(number: 4, text: "生成后按引导设置为壁纸", color: .accentGreen)
+                    QuickStartStep(number: 1, text: String(localized: "home.quickStart.step1"), color: .accentPurple)
+                    QuickStartStep(number: 2, text: String(localized: "home.quickStart.step2"), color: .accentCyan)
+                    QuickStartStep(number: 3, text: String(localized: "home.quickStart.step3"), color: .accentPink)
+                    QuickStartStep(number: 4, text: String(localized: "home.quickStart.step4"), color: .accentGreen)
                 }
 
                 HStack {
                     Spacer()
-                    Text("完成后的作品会显示在这里")
+                    Text(String(localized: "home.emptyHint"))
                         .font(.system(size: DesignTokens.FontSize.xs))
                         .foregroundColor(.textMuted)
                     Spacer()
@@ -190,13 +190,13 @@ struct HomeView: View {
                         .foregroundColor(.accentCyan)
                 }
 
-                Text("最近作品")
+                Text(String(localized: "home.recentWorks"))
                     .font(.system(size: DesignTokens.FontSize.lg, weight: .semibold))
                     .foregroundColor(.textPrimary)
 
                 Spacer()
 
-                Text("\(recentWorks.recentWorks.count) 个")
+                Text(String(localized: "home.worksCount \(recentWorks.recentWorks.count)"))
                     .font(.system(size: DesignTokens.FontSize.sm))
                     .foregroundColor(.textMuted)
             }
@@ -224,7 +224,7 @@ struct HomeView: View {
 
         do {
             guard let movie = try await item.loadTransferable(type: VideoTransferable.self) else {
-                errorMessage = "无法加载视频"
+                errorMessage = String(localized: "home.loadFailed")
                 isLoading = false
                 return
             }