fix(comments): render image upload progress like the reference

While uploading, the confirm button turned into a thin 3px bar below the
label instead of the reference's striped overlay that fills the button.

Two causes:
- the markup used <span class="progress">; Bootstrap sizes the bar with a
  block-level .progress, so the swap produced a flattened line
- shell.css carried a bespoke override pinning .progress to
  `position: static; height: 3px`, discarding the absolute full-size
  overlay that main.css already provides

Changes:
- emit the reference skeleton: <div class="progress progress-striped active">
  > <div class="progress-bar progress-bar-success">, so the striped bar
  spans the button and the gradient shows through the translucent layer
- give the upload button `position: relative` so the overlay is contained by
  the button rather than the dropdown panel; delete the static-line override
- restore the reference's "正在处理请稍等..." toast and switch the label to
  "处理中 ..." at 100%, both keyed to the shared `miniupload_ajax` toast id
  so the completion message replaces the loading one
- notify() now forwards the toast id instead of dropping it

Tests: comment-image-upload contract gains two cases pinning the div-based
striped overlay and the deletion of the 3px override; suite 835/836 with the
pre-existing frontend-lifecycle failure.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

tests/widget-system/comment-image-upload-contract.test.cjs

@@ -78,3 +78,31 @@ test('built comment assets carry the upload contract and no removed submit handl
   assert.match(commentsCss, /progress-bar/);
   assert.doesNotMatch(runtimeBundle, /handleResponse/);
 });
+
+test('上传中骨架与参考主题一致：Bootstrap 条纹进度层铺满按钮', () => {
+  // 参考结构：<span class="miniupload-ing"> + <div class="progress progress-striped active">
+  // 内层 <div class="progress-bar progress-bar-success">，用 div 而非 span。
+  assert.match(
+    tools,
+    /'<span class="miniupload-ing">'[\s\S]{0,400}'<div class="progress progress-striped active"><div class="progress-bar progress-bar-success" role="progressbar" style="width:0"><\/div><\/div>'/,
+    '上传中骨架必须复用参考主题的 miniupload-ing + Bootstrap 条纹进度层'
+  );
+  assert.doesNotMatch(tools, /<span class="progress progress-striped/, '进度层必须是 div，span 会破坏 Bootstrap 的块级布局');
+  assert.match(tools, /window\.notyf\('正在处理请稍等\.\.\.', 'load', '', 'miniupload_ajax'\)/, '上传开始应弹出参考主题的「正在处理」提示');
+  assert.match(tools, /loadingText\.innerHTML = '处理中 \.\.\.'/, '到达 100% 后文案切换为「处理中 ...」');
+});
+
+test('上传按钮提供定位上下文，并去掉自造的静态细条覆盖', () => {
+  const shell = read('assets/css/frontend/comments/shell.css');
+  assert.match(
+    shell,
+    /#comments \.comment-image-upload \.input-expand-upload \{[\s\S]*?position: relative;/,
+    '.progress 是绝对铺满层，按钮必须是定位祖先'
+  );
+  assert.doesNotMatch(
+    shell,
+    /#comments \.comment-image-upload \.progress \{[\s\S]{0,200}position: static/,
+    '不得再把 .progress 改成静态细条（偏离参考主题）'
+  );
+  assert.doesNotMatch(shell, /height: 3px;[\s\S]{0,80}#comments \.comment-image-upload \.progress/, '自造的 3px 细条已删除');
+});