feat(compose): 正文内嵌隐藏块并升级 Markdown 编辑器

去掉整帖可见性表单，改为 :::hide 按块脱敏；工具栏补齐代码块、链接/图片对话框与粘贴拖拽上传。

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/components/MarkdownBodyClient.tsx

@@ -3,30 +3,64 @@
 import ReactMarkdown, { type Components } from "react-markdown";
 import remarkGfm from "remark-gfm";
 import { mergeMarkdownComponents } from "@/components/markdown/mergeComponents";
+import { splitHideSegments, type HideKind } from "@/lib/hideBlocks";
+import MdHideBlock from "@/components/markdown/MdHideBlock";
 
 type MarkdownBodyClientProps = {
   content: string;
   className?: string;
   components?: Components;
+  postId?: number;
+  loggedIn?: boolean;
 };
 
 /**
- * 客户端 Markdown（发帖预览 / 评论）：GFM + 图箱 / 代码折叠复制。
- * 语法高亮在 MdCodeBlock 内按需用 Shiki 补齐。
+ * 客户端 Markdown（发帖预览 / 评论）：GFM + 隐藏块徽章预览。
  */
 export default function MarkdownBodyClient({
   content,
   className = "prose-content",
   components,
+  postId,
+  loggedIn = false,
 }: MarkdownBodyClientProps) {
+  const segs = splitHideSegments(content || "");
+  const mdComponents = mergeMarkdownComponents(components);
+
   return (
     <div className={className}>
-      <ReactMarkdown
-        remarkPlugins={[remarkGfm]}
-        components={mergeMarkdownComponents(components)}
-      >
-        {content || ""}
-      </ReactMarkdown>
+      {segs.map((seg, i) => {
+        if (seg.type === "md") {
+          if (!seg.text.trim()) return null;
+          return (
+            <ReactMarkdown key={`md-${i}`} remarkPlugins={[remarkGfm]} components={mdComponents}>
+              {seg.text}
+            </ReactMarkdown>
+          );
+        }
+        const kind = seg.kind as HideKind;
+        if (seg.locked) {
+          return (
+            <MdHideBlock
+              key={`hide-${i}`}
+              kind={kind}
+              points={seg.points}
+              locked
+              postId={postId}
+              loggedIn={loggedIn}
+            />
+          );
+        }
+        return (
+          <MdHideBlock key={`hide-${i}`} kind={kind} points={seg.points}>
+            {seg.body.trim() ? (
+              <ReactMarkdown remarkPlugins={[remarkGfm]} components={mdComponents}>
+                {seg.body}
+              </ReactMarkdown>
+            ) : null}
+          </MdHideBlock>
+        );
+      })}
     </div>
   );
 }