feat: set English as default language

1. Change default language to English
2. Update coin display names to full English names
3. Improve language switch text
4. Convert comments to English
5. Fix language toggle text

Author: chenchenwuai

main.swift

@@ -25,7 +25,7 @@ class AppDelegate: NSObject, NSApplicationDelegate {
         ("DOGE", "DOGEUSDT", "Ð")
     ]
 
-    // 语言本地化
+    // Localization
     private let localizedStrings: [String: [Bool: String]] = [
         "loading": [true: "Loading...", false: "加载中..."],
         "addCoin": [true: "Add Custom Coin...", false: "添加自定义币种..."],
@@ -81,7 +81,7 @@ class AppDelegate: NSObject, NSApplicationDelegate {
     func applicationDidFinishLaunching(_ aNotification: Notification) {
         statusItem = NSStatusBar.system.statusItem(withLength: NSStatusItem.variableLength)
 
-        // 设置菜单栏显示
+        // Set up menu bar display
         if let button = statusItem.button {
             button.image = nil
             button.title = "\(currentIcon) \(currentPrice)"
@@ -167,7 +167,7 @@ class AppDelegate: NSObject, NSApplicationDelegate {
             currentApiIndex = index
             isAutoSwitchApi = false
             setupMenu()
-            updatePrice() // 立即更新价格以测试新API
+            updatePrice() // Update price immediately to test new API
         }
     }
 
@@ -181,7 +181,7 @@ class AppDelegate: NSObject, NSApplicationDelegate {
     }
 
     func validateAndAddCoin(_ symbol: String) {
-        // 检查是否已存在
+        // Check if the coin already exists
         if symbols.contains(where: { $0.1 == symbol }) {
             DispatchQueue.main.async {
                 self.currentSymbol = symbol
@@ -220,10 +220,7 @@ class AppDelegate: NSObject, NSApplicationDelegate {
     }
 
     func formatPrice(_ price: Double) -> String {
-        // 对于小于0.01的价格显示8位小数
-        // 对于0.01-1之间的价格显示6位小数
-        // 对于1-100之间的价格显示4位小数
-        // 对于100以上的价格显示2位小数
+        // Format price based on its value
         let decimals: Int
         if price < 0.01 {
             decimals = 8
@@ -235,10 +232,10 @@ class AppDelegate: NSObject, NSApplicationDelegate {
             decimals = 2
         }
 
-        // 格式化价格
+        // Format price
         let formattedPrice = String(format: "%.\(decimals)f", price)
 
-        // 移除末尾的0，但保留小数点后至少一位
+        // Remove trailing zeros, but keep at least one decimal place
         var trimmed = formattedPrice
         while trimmed.hasSuffix("0") && trimmed.contains(".") && trimmed.split(separator: ".")[1].count > 1 {
             trimmed.removeLast()
@@ -290,7 +287,7 @@ class AppDelegate: NSObject, NSApplicationDelegate {
 
         NSApp.activate(ignoringOtherApps: true)
 
-        // 显示对话框
+        // Show alert
         let response = alert.runModal()
 
         if response == .alertFirstButtonReturn {
@@ -359,11 +356,11 @@ class AppDelegate: NSObject, NSApplicationDelegate {
         let alert = NSAlert()
         alert.messageText = localized("aboutTitle")
         alert.informativeText = localized("aboutMessage")
-        alert.window.maxSize = NSSize(width: 500, height: 1000)  // 增加最大宽度
-        alert.window.minSize = NSSize(width: 400, height: 200)   // 设置最小宽度
+        alert.window.maxSize = NSSize(width: 500, height: 1000)  // Increase maximum width
+        alert.window.minSize = NSSize(width: 400, height: 200)   // Set minimum width
         alert.alertStyle = .informational
 
-        // 添加应用图标
+        // Add application icon
         if let iconURL = Bundle.main.url(forResource: "AppIcon", withExtension: "icns"),
            let image = NSImage(contentsOf: iconURL) {
             alert.icon = image