feat: add i18n support and app icon in top-left corner

- Added i18n JSON files (zh.json, en.json) with auto language detection
- Updated miniplayer.ui to use i18n keys for all button labels
- Added MiniPlayerIcon overlay in top-left corner of main window
- Load i18n translations on app startup based on system locale

Sources/MiniPlayerApp.swift

@@ -15,6 +15,7 @@ struct MiniPlayerApp: App {
                 .onAppear {
                     bridge.setup()
                     setupBridgeEvents()
+                    loadI18n()
                 }
         }
         #if os(macOS)
@@ -108,6 +109,20 @@ struct MiniPlayerApp: App {
             bridge.openFileDialog()
         }
     }
+    
+    // 加载 i18n 翻译
+    private func loadI18n() {
+        // 检测系统语言
+        let locale = Locale.current.language.languageCode?.identifier ?? "en"
+        let langFile = (locale == "zh") ? "zh" : "en"
+        
+        if let url = Bundle.module.url(forResource: "i18n/\(langFile)", withExtension: "json"),
+           let data = try? Data(contentsOf: url),
+           let dict = try? JSONSerialization.jsonObject(with: data) as? [String: String] {
+            engine.i18n.loadMessages(dict)
+            engine.i18n.locale = langFile
+        }
+    }
 }
 
 // MARK: - BricksView wrapper
@@ -117,7 +132,7 @@ struct BricksAppView: View {
     @State private var jsonString: String?
     
     var body: some View {
-        ZStack {
+        ZStack(alignment: .topLeading) {
             if let json = jsonString {
                 BricksView(json: json, engine: engine)
             } else {
@@ -126,6 +141,11 @@ struct BricksAppView: View {
                         jsonString = loadJSONString()
                     }
             }
+            
+            // 左上角应用图标
+            MiniPlayerIcon()
+                .frame(width: 32, height: 32)
+                .padding(12)
         }
         .sheet(isPresented: $bridge.showURLDialog) {
             URLInputDialog(bridge: bridge)

Sources/Resources/i18n/en.json

@@ -0,0 +1,9 @@
+{
+  "open": "Open",
+  "prev": "Prev",
+  "play_pause": "Play/Pause",
+  "next": "Next",
+  "url_placeholder": "Enter video URL...",
+  "load": "Load",
+  "fullscreen": "Fullscreen"
+}

Sources/Resources/i18n/zh.json

@@ -0,0 +1,9 @@
+{
+  "open": "打开",
+  "prev": "上一个",
+  "play_pause": "播放/暂停",
+  "next": "下一个",
+  "url_placeholder": "输入视频URL...",
+  "load": "加载",
+  "fullscreen": "全屏"
+}

Sources/Resources/miniplayer.ui

@@ -28,7 +28,7 @@
           "widgettype": "Button",
           "id": "openBtn",
           "options": {
-            "label": "Open",
+            "label": "open",
             "icon": "folder",
             "cwidth": 8,
             "cheight": 4,
@@ -48,7 +48,7 @@
           "widgettype": "Button",
           "id": "prevBtn",
           "options": {
-            "label": "Prev",
+            "label": "prev",
             "icon": "backward.fill",
             "cwidth": 8,
             "cheight": 4,
@@ -68,7 +68,7 @@
           "widgettype": "Button",
           "id": "toggleBtn",
           "options": {
-            "label": "Play/Pause",
+            "label": "play_pause",
             "icon": "playpause.fill",
             "cwidth": 12,
             "cheight": 4,
@@ -88,7 +88,7 @@
           "widgettype": "Button",
           "id": "nextBtn",
           "options": {
-            "label": "Next",
+            "label": "next",
             "icon": "forward.fill",
             "cwidth": 8,
             "cheight": 4,
@@ -112,7 +112,7 @@
           "id": "videoUrlInput",
           "options": {
             "name": "url",
-            "placeholder": "Enter video URL...",
+            "placeholder": "url_placeholder",
             "cwidth": 30,
             "cheight": 4
           }
@@ -121,7 +121,7 @@
           "widgettype": "Button",
           "id": "loadBtn",
           "options": {
-            "label": "Load",
+            "label": "load",
             "icon": "arrow.down.circle.fill",
             "cwidth": 8,
             "cheight": 4,
@@ -142,7 +142,7 @@
           "widgettype": "Button",
           "id": "fullscreenBtn",
           "options": {
-            "label": "Fullscreen",
+            "label": "fullscreen",
             "icon": "arrow.up.left.and.arrow.down.right",
             "cwidth": 10,
             "cheight": 4,