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/app/post/[id]/page.tsx

@@ -34,7 +34,7 @@ import MobilePostBar from "@/components/MobilePostBar";
 import Avatar from "@/components/Avatar";
 import RoleBadge from "@/components/RoleBadge";
 import MarkdownBody from "@/components/MarkdownBody";
-import ContentLockGate from "@/components/ContentLockGate";
+import { publicMarkdownForSeo } from "@/lib/hideBlocks";
 import PostAttachments from "@/components/PostAttachments";
 import PostInteractPanels, { QuestionStatusCard } from "@/components/PostInteractPanels";
 import AcceptedAnswerCard from "@/components/AcceptedAnswerCard";
@@ -60,9 +60,10 @@ export async function generateMetadata({ params }: PageProps): Promise<Metadata>
         robots: { index: false, follow: false },
       };
     }
-    const desc = post.content_locked
-      ? post.access_hint || "部分内容需满足条件后可见"
-      : (post.content || "").slice(0, 160);
+    const publicBody = publicMarkdownForSeo(post.content || "");
+    const desc = publicBody
+      ? publicBody.slice(0, 160)
+      : post.access_hint || "部分内容需满足条件后可见";
     return {
       title: post.title,
       description: desc,
@@ -481,10 +482,11 @@ export default async function PostDetailPage({ params, searchParams }: PageProps
   const related = (relatedData?.posts ?? []).filter((p) => p.id !== post.id).slice(0, 5);
   const authorPosts = (profile?.posts ?? []).filter((p) => p.id !== post.id).slice(0, 5);
 
-  const toc = post.content_locked ? [] : extractToc(post.content);
+  const publicBody = publicMarkdownForSeo(post.content || "");
+  const toc = extractToc(publicBody);
   const readingMinutes = Math.max(
     1,
-    Math.ceil((post.content_locked ? post.title.length : post.content.length) / 400)
+    Math.ceil((publicBody.length > 0 ? publicBody.length : post.title.length) / 400)
   );
   const edited =
     new Date(post.updated_at).getTime() - new Date(post.created_at).getTime() > 60_000;
@@ -527,8 +529,8 @@ export default async function PostDetailPage({ params, searchParams }: PageProps
     "@context": "https://schema.org",
     "@type": "DiscussionForumPosting",
     headline: post.title,
-    // 锁定正文不进 JSON-LD，避免 SEO 泄露付费/回复可见内容
-    articleBody: post.content_locked ? undefined : post.content,
+    // 仅公开片段进 JSON-LD，避免 SEO 泄露隐藏块原文
+    articleBody: publicBody || undefined,
     datePublished: post.created_at,
     dateModified: post.updated_at,
     author: { "@type": "Person", name: post.user.nickname },
@@ -541,7 +543,7 @@ export default async function PostDetailPage({ params, searchParams }: PageProps
     ...(allowComments &&
       acceptedAnswer &&
       !acceptedAnswer.deleted &&
-      !post.content_locked && {
+      !!publicBody && {
         acceptedAnswer: {
           "@type": "Comment",
           text: acceptedAnswer.content,
@@ -718,24 +720,14 @@ export default async function PostDetailPage({ params, searchParams }: PageProps
                 </div>
               )}
 
-              {post.content_locked ? (
-                <ContentLockGate
-                  postId={post.id}
-                  hint={post.access_hint}
-                  access={post.content_access}
-                  points={post.access_points}
-                  loggedIn={!!me.user}
-                />
-              ) : (
-                <MarkdownBody
-                  content={post.content}
-                  components={{ h2: headingRenderer("h2"), h3: headingRenderer("h3") }}
-                />
-              )}
+              <MarkdownBody
+                content={post.content}
+                postId={post.id}
+                loggedIn={!!me.user}
+                components={{ h2: headingRenderer("h2"), h3: headingRenderer("h3") }}
+              />
 
-              {!post.content_locked && (
-                <PostAttachments postId={post.id} items={post.attachments || []} />
-              )}
+              <PostAttachments postId={post.id} items={post.attachments || []} />
 
               {/* 类型特殊块（投票/悬赏/抽奖/问答）统一放正文最下方 */}
               <PostInteractPanels
@@ -745,7 +737,7 @@ export default async function PostDetailPage({ params, searchParams }: PageProps
                 lottery={post.lottery}
                 loggedIn={!!me.user}
               />
-              {!post.content_locked && allowComments && acceptedAnswer ? (
+              {allowComments && acceptedAnswer ? (
                 <AcceptedAnswerCard
                   answer={acceptedAnswer}
                   variant={acceptedAnswerVariant}