标题栏改为更多菜单，支持复制和清除

Note/FormatterView.swift

@@ -54,11 +54,18 @@ struct FormatterView: View {
                 .font(.largeTitle.bold())
                 .foregroundStyle(.primary)
             Spacer()
-            if !inputText.isEmpty {
+            Menu {
                 Button(action: copyText) {
-                    Image(systemName: "doc.on.doc")
+                    Label("复制", systemImage: "doc.on.doc")
                 }
-                .font(.title3)
+                .disabled(inputText.isEmpty)
+                Button(role: .destructive, action: clearText) {
+                    Label("清除", systemImage: "xmark.circle")
+                }
+                .disabled(inputText.isEmpty)
+            } label: {
+                Image(systemName: "ellipsis.circle")
+                    .font(.title3)
             }
         }
         .frame(maxWidth: .infinity, minHeight: 44)
@@ -175,6 +182,10 @@ struct FormatterView: View {
             }
         }
     }
+
+    private func clearText() {
+        inputText = ""
+    }
 }
 
 #Preview {