feat: 站点单页、时间线导入与行级 BBCode 短代码

首页右栏接入单页入口与公告置顶/全部页；Markdown 编辑器支持可视化时间线与 Git 导入；隐藏块改为 [hide]/[timeline] 命名闭合，并修复单页/公告 GORM 更新只改 updated_at 的问题。

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

frontend/components/MarkdownBodyClient.tsx

@@ -3,28 +3,32 @@
 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 { splitContentSegments } from "@/lib/directiveBlocks";
+import type { HideKind } from "@/lib/hideBlocks";
 import MdHideBlock from "@/components/markdown/MdHideBlock";
+import MdTimeline from "@/components/markdown/MdTimeline";
 
 type MarkdownBodyClientProps = {
   content: string;
   className?: string;
   components?: Components;
   postId?: number;
+  loginHref?: string;
   loggedIn?: boolean;
 };
 
 /**
- * 客户端 Markdown（发帖预览 / 评论）：GFM + 隐藏块徽章预览。
+ * 客户端 Markdown（发帖预览 / 评论）：GFM + 隐藏块 / 时间线预览。
  */
 export default function MarkdownBodyClient({
   content,
   className = "prose-content",
   components,
   postId,
+  loginHref,
   loggedIn = false,
 }: MarkdownBodyClientProps) {
-  const segs = splitHideSegments(content || "");
+  const segs = splitContentSegments(content || "");
   const mdComponents = mergeMarkdownComponents(components);
 
   return (
@@ -38,6 +42,21 @@ export default function MarkdownBodyClient({
             </ReactMarkdown>
           );
         }
+        if (seg.type === "timeline") {
+          return (
+            <MdTimeline
+              key={`tl-${i}`}
+              items={seg.items}
+              renderBody={(it) =>
+                it.body.trim() ? (
+                  <ReactMarkdown remarkPlugins={[remarkGfm]} components={mdComponents}>
+                    {it.body}
+                  </ReactMarkdown>
+                ) : null
+              }
+            />
+          );
+        }
         const kind = seg.kind as HideKind;
         if (seg.locked) {
           return (
@@ -47,6 +66,7 @@ export default function MarkdownBodyClient({
               points={seg.points}
               locked
               postId={postId}
+              loginHref={loginHref}
               loggedIn={loggedIn}
             />
           );