fix: SettingsWindow 输入框支持 Cmd+A/C/V/X 快捷键

Sources/UI/SettingsWindow.swift

@@ -40,6 +40,35 @@ final class SettingsWindow: NSWindow {
         center()
     }
 
+    // MARK: - 快捷键支持（LSUIElement 无 Edit 菜单，需手动转发）
+
+    override func performKeyEquivalent(with event: NSEvent) -> Bool {
+        // 仅拦截 Cmd 组合键
+        guard event.modifierFlags.contains(.command) else {
+            return super.performKeyEquivalent(with: event)
+        }
+
+        let selector: Selector?
+        switch event.charactersIgnoringModifiers?.lowercased() {
+        case "a": selector = #selector(NSText.selectAll(_:))
+        case "c": selector = Selector(("copy:"))
+        case "v": selector = Selector(("paste:"))
+        case "x": selector = Selector(("cut:"))
+        default: selector = nil
+        }
+
+        guard let sel = selector else {
+            return super.performKeyEquivalent(with: event)
+        }
+
+        // 发送到第一响应者链
+        if NSApp.sendAction(sel, to: nil, from: self) {
+            return true
+        }
+
+        return super.performKeyEquivalent(with: event)
+    }
+
     private func buildUI() {
         guard let content = contentView else { return }