fix single-post.css

tests/widget-system/single-cover-height-contract.test.cjs

@@ -101,6 +101,27 @@ test('video cover: the player video fills and center-crops like the image cover'
   );
 });
 
+test('resource singles get the cover leaf versioned, never via the aggregate @import', () => {
+  // 聚合文件的 @import 无版本号：浏览器会拿旧缓存（含已废弃的 .single-cover
+  // padding 规则）把封面高度链挤成 0，资源型文章封面直接空白。
+  assert.doesNotMatch(
+    read('assets/css/frontend/single-post.css'),
+    /@import[^;]*single-post\/cover\.css/,
+    '聚合样式不得再 @import cover leaf'
+  );
+  const enqueue = read('src/Core/ScriptsPart1b.php');
+  assert.match(
+    enqueue,
+    /if \(!empty\(\$singular_assets\['needs_cover'\]\)\) \{[\s\S]{0,400}?single-post\/cover\.css/,
+    '资源单页必须按 needs_cover 以 filemtime 版本号入队 cover leaf'
+  );
+  assert.match(
+    enqueue,
+    /'aksrt-single-post-cover'/,
+    'cover leaf 句柄与文章分支命名保持一致'
+  );
+});
+
 test('single cover css owns no fallback padding and the scale var is gone', () => {
   for (const file of [
     'assets/css/frontend/single-post/cover.css',