feat(creator-studio): portal dropdowns, hidden content, two-step block delete

Toolbar
- New ToolMenu renders menus through a portal on body, so they are no longer
  clipped by the horizontally scrolling toolbar and no longer fall back to a
  native <select>. Triggers reuse .jio-creator__tool-btn geometry, fixing the
  heading button's mismatched height/size/position.
- Heading / list / align / quote / hidden-content are all dropdowns.
- Lists: unordered + ordered via InsertOrderedList/InsertUnorderedList.
  The TOC button is removed (it also used the wrong icon).
- Adds left / center / right alignment.
- Adds hidden content: comment / login / VIP / paid, wired to the existing
  [reply], [jio_hide mode="login"], [vip] and [payshow] shortcodes.

Editor content
- Quote blocks now match the live article: full .quote_q structure, four
  colour variables, and an SVG-mask quote mark that does not depend on the
  Font Awesome font being present inside the iframe.
- Block math is centred on a transparent background instead of a full-width
  grey bar.
- Code blocks are plain <pre><code>, identical to the article page; language
  and theme selection is gone and EnlighterJS handles highlighting globally.
  The classic submit editor's code modal follows the same shape.
- Hidden content reuses the .tinymce-hide structure and shows a readable label
  while keeping the shortcode text in the DOM for saving.

Block deletion
- Two-step delete, WPS style: the first click only selects and highlights the
  block, the second click removes it. Clicking elsewhere or Esc cancels.

Contracts updated and extended; 884 widget-system tests pass.

assets/css/frontend/pages/submit-editor.css

@@ -1,4 +1,6 @@
 /* Content shown inside the front-submit TinyMCE iframe. */
+
+/* 隐藏内容：短代码留在 .hide-before / .hide-after，编辑器只显示可读标签。 */
 .tinymce-hide {
   position: relative;
   margin: 18px 0;
@@ -13,7 +15,7 @@
   margin: 0;
   color: #f04494;
   font-family: Consolas, Monaco, monospace;
-  font-size: 12px;
+  font-size: 0;
   line-height: 1.5;
 }
 
@@ -23,8 +25,16 @@
   left: 14px;
 }
 
+.tinymce-hide > .hide-before::before {
+  content: attr(data-jio-hide-label);
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
+  font-size: 12px;
+  font-weight: 600;
+  letter-spacing: 0.02em;
+}
+
 .tinymce-hide > .hide-after {
-  margin-top: 8px;
+  display: none;
 }
 
 .tinymce-hide > [contenteditable="true"] {
@@ -105,23 +115,30 @@
   --quote-color: #23790e;
 }
 
-.enlighter-pre {
-  position: relative;
-  max-height: 300px;
-  overflow: auto;
-  padding: 32px 12px 12px;
-  border-radius: 6px;
+/* 代码块：与前台文章页一致，只用 pre > code，由 EnlighterJS 在发布页高亮。 */
+pre {
+  margin: 0 0 1.1em;
+  padding: 14px 18px;
+  overflow-x: auto;
+  border-radius: 8px;
   background: #f2f4f5;
+  color: #2b2b2b;
+  font-family: Consolas, Monaco, "Courier New", monospace;
+  font-size: 13px;
+  line-height: 1.6;
+  white-space: pre-wrap;
+  word-wrap: break-word;
 }
 
-.enlighter-pre code.gl {
-  display: block;
+pre code {
   border: 0;
   background: transparent;
   color: inherit;
-  font-family: Consolas, Monaco, monospace;
-  line-height: 1.45;
-  white-space: break-spaces;
+  font-family: inherit;
+  font-size: inherit;
+  line-height: inherit;
+  padding: 0;
+  white-space: inherit;
 }
 
 .file-download-box {