Refactor Settings, FileTree, GitPanel, Shell, and CodeEditor components (#402)

src/components/standalone-shell/view/subcomponents/StandaloneShellHeader.tsx

@@ -0,0 +1,30 @@
+type StandaloneShellHeaderProps = {
+  title: string;
+  isCompleted: boolean;
+  onClose?: (() => void) | null;
+};
+
+export default function StandaloneShellHeader({
+  title,
+  isCompleted,
+  onClose = null,
+}: StandaloneShellHeaderProps) {
+  return (
+    <div className="flex-shrink-0 bg-gray-800 border-b border-gray-700 px-4 py-2">
+      <div className="flex items-center justify-between">
+        <div className="flex items-center space-x-2">
+          <h3 className="text-sm font-medium text-gray-200">{title}</h3>
+          {isCompleted && <span className="text-xs text-green-400">(Completed)</span>}
+        </div>
+
+        {onClose && (
+          <button onClick={onClose} className="text-gray-400 hover:text-white" title="Close">
+            <svg className="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" />
+            </svg>
+          </button>
+        )}
+      </div>
+    </div>
+  );
+}