feat: 论坛 emoji 表情支持

- 新增 dyEmoji 表情库与解析测试、EmojiPicker 选择器与 EmojiImg 组件
- Markdown 编辑器/渲染支持表情图片，新增 public/emoji 资源与生成脚本
- 聊天室与首页适配

frontend/components/MarkdownEditor.tsx

@@ -32,12 +32,14 @@ import {
   ChevronDown,
   History,
   Ellipsis,
+  Smile,
 } from "lucide-react";
 import { apiSearchPosts, apiUploadPostImage, type PostListItem } from "@/lib/api";
 import { toast } from "@/lib/toast";
 import MarkdownBodyClient from "@/components/MarkdownBodyClient";
 import ImageInsertModal from "@/components/ImageInsertModal";
 import TimelineEditor from "@/components/TimelineEditor";
+import EmojiPicker from "@/components/EmojiPicker";
 import { resolveTimelineBlockForEdit } from "@/lib/directiveBlocks";
 import { SHIKI_LANG_IDS } from "@/components/markdown/shikiHighlighter";
 import { postPath } from "@/lib/urlStyle";
@@ -88,7 +90,7 @@ type WrapOpts = {
   linePrefix?: string;
 };
 
-type PopoverKind = "link" | "code" | "hide" | "heading" | "more" | null;
+type PopoverKind = "link" | "code" | "hide" | "heading" | "more" | "emoji" | null;
 
 const CODE_LANGS = ["plaintext", "aardio", ...SHIKI_LANG_IDS.filter((l) => l !== "plaintext")] as const;
 
@@ -412,6 +414,36 @@ export default function MarkdownEditor({
     [value, onChange]
   );
 
+  /** 行内插入（无换行 padding）：表情等短代码用 */
+  const insertInline = useCallback(
+    (text: string) => {
+      const el = taRef.current;
+      if (!el) {
+        onChange(value + text);
+        return;
+      }
+      const start = savedSel.current?.start ?? el.selectionStart;
+      const end = savedSel.current?.end ?? el.selectionEnd;
+      const next = value.slice(0, start) + text + value.slice(end);
+      onChange(next);
+      requestAnimationFrame(() => {
+        el.focus();
+        const caret = start + text.length;
+        el.setSelectionRange(caret, caret);
+      });
+      savedSel.current = null;
+    },
+    [value, onChange]
+  );
+
+  const pickEmoji = useCallback(
+    (key: string) => {
+      insertInline(`[:${key}:]`);
+      setPopover(null);
+    },
+    [insertInline]
+  );
+
   const uploadImageFile = async (file: File | null) => {
     if (!file || disabled) return;
     retryFile.current = file;
@@ -976,6 +1008,19 @@ export default function MarkdownEditor({
               </div>
             )}
           </div>
+          <div className="j13-md-popover-anchor relative">
+            <ToolBtn
+              label="表情"
+              icon={<Smile size={15} />}
+              active={popover === "emoji"}
+              onClick={() => openPopover("emoji")}
+            />
+            {popover === "emoji" && (
+              <div className="j13-md-popover j13-md-emoji-popover" role="dialog" aria-label="插入表情">
+                <EmojiPicker onPick={pickEmoji} />
+              </div>
+            )}
+          </div>
           <div className="j13-md-popover-anchor relative">
             <ToolBtn
               label={uploading ? "上传中…" : "图片"}