style: match image editor navbar height with homepage (h-12)

components/image-annotator.tsx

@@ -1216,8 +1216,8 @@ export function ImageAnnotator({ imageUrl, onConfirm, onCancel, initialResizeMod
         className="flex flex-col overflow-hidden w-full h-full"
         onClick={(e) => e.stopPropagation()}
       >
-        {/* 顶部标题栏 - 始终深色模式 */}
-        <div className="flex items-center justify-between border-b border-zinc-700 px-4 py-3 bg-zinc-900 text-white">
+        {/* 顶部标题栏 - 始终深色模式，高度与首页导航栏一致 */}
+        <div className="flex items-center justify-between border-b border-zinc-700 px-4 h-12 bg-zinc-900 text-white">
           <Link 
             href="/" 
             className="flex items-center gap-2 hover:opacity-80 transition-opacity"