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/lib/dyEmoji.test.ts

@@ -0,0 +1,100 @@
+import assert from "node:assert/strict";
+import { describe, it } from "node:test";
+import { readFileSync } from "node:fs";
+import { fileURLToPath } from "node:url";
+import {
+  DY_EMOJI_ALIASES,
+  DY_EMOJI_GROUPS,
+  DY_EMOJI_RE,
+  dyEmojiFileKey,
+  dyEmojiUrl,
+  expandDyEmojiShortcodes,
+} from "./dyEmoji.ts";
+
+const CAT_HASH = DY_EMOJI_ALIASES["猫猫"];
+
+describe("DY_EMOJI_ALIASES", () => {
+  it("中文语义名 → hash 文件名，文件名全局唯一", () => {
+    assert.match(CAT_HASH, /^[A-Za-z0-9_-]+$/);
+    const files = Object.values(DY_EMOJI_ALIASES);
+    assert.equal(new Set(files).size, files.length);
+  });
+  it("完整覆盖 manifest.tos（集合一致；面板分组顺序独立于 manifest）", () => {
+    const manifest = JSON.parse(
+      readFileSync(fileURLToPath(new URL("../public/emoji/dy/manifest.json", import.meta.url)), "utf8")
+    );
+    assert.deepEqual(Object.values(DY_EMOJI_ALIASES).sort(), [...manifest.tos].sort());
+  });
+});
+
+describe("DY_EMOJI_GROUPS", () => {
+  it("分组 keys 无重复", () => {
+    const all = DY_EMOJI_GROUPS.flatMap((g) => g.keys);
+    assert.equal(new Set(all).size, all.length);
+  });
+  it("分组 keys 恰好覆盖全部中文语义名（不多不少）", () => {
+    const grouped = DY_EMOJI_GROUPS.flatMap((g) => g.keys).sort();
+    const allKeys = Object.keys(DY_EMOJI_ALIASES).sort();
+    assert.deepEqual(grouped, allKeys);
+  });
+});
+
+describe("dyEmojiFileKey / dyEmojiUrl", () => {
+  it("中文 key 解析为实际文件名，合成表情组合名透传", () => {
+    assert.equal(dyEmojiFileKey("猫猫"), CAT_HASH);
+    assert.equal(dyEmojiFileKey("001--002--heart"), "001--002--heart");
+  });
+  it("拼接扁平目录 URL", () => {
+    assert.equal(dyEmojiUrl("猫猫"), `/emoji/dy/${CAT_HASH}.png`);
+    assert.equal(dyEmojiUrl("001--002--heart"), "/emoji/dy/001--002--heart.png");
+  });
+  it("未知 key 原样 URL 编码透传", () => {
+    assert.equal(dyEmojiUrl("不存在"), `/emoji/dy/${encodeURIComponent("不存在")}.png`);
+  });
+});
+
+describe("expandDyEmojiShortcodes", () => {
+  it("中文短代码替换为 markdown 图片", () => {
+    assert.equal(
+      expandDyEmojiShortcodes("你好[:猫猫:]!"),
+      `你好![dy:猫猫](/emoji/dy/${CAT_HASH}.png)!`
+    );
+  });
+  it("合成表情组合名短代码", () => {
+    assert.equal(
+      expandDyEmojiShortcodes("[:001--002--heart:]"),
+      "![dy:001--002--heart](/emoji/dy/001--002--heart.png)"
+    );
+  });
+  it("多次替换且共享前缀", () => {
+    assert.equal(
+      expandDyEmojiShortcodes("[:猫猫:][:aa:][:猫猫:]"),
+      `![dy:猫猫](/emoji/dy/${CAT_HASH}.png)![dy:aa](/emoji/dy/aa.png)![dy:猫猫](/emoji/dy/${CAT_HASH}.png)`
+    );
+  });
+  it("无短代码时原样返回", () => {
+    const s = "普通文本 [a:] :x: [[y]]";
+    assert.equal(expandDyEmojiShortcodes(s), s);
+    assert.equal(expandDyEmojiShortcodes(""), "");
+  });
+  it("非法 key 不匹配（含 . / 空 / @ / 空白）", () => {
+    assert.equal(expandDyEmojiShortcodes("[:a.b:][:]"), "[:a.b:][:]");
+    assert.equal(expandDyEmojiShortcodes("[:空 格:]"), "[:空 格:]");
+    assert.equal(expandDyEmojiShortcodes("[:@x:]"), "[:@x:]");
+  });
+  it("跨行文本", () => {
+    assert.equal(
+      expandDyEmojiShortcodes("第一行[:猫猫:]\n第二行"),
+      `第一行![dy:猫猫](/emoji/dy/${CAT_HASH}.png)\n第二行`
+    );
+  });
+  it("连续使用共享同一正则（lastIndex 复用安全）", () => {
+    assert.equal(expandDyEmojiShortcodes("[:猫猫:]"), `![dy:猫猫](/emoji/dy/${CAT_HASH}.png)`);
+    assert.equal(expandDyEmojiShortcodes("[:b:]"), "![dy:b](/emoji/dy/b.png)");
+    assert.equal(expandDyEmojiShortcodes("纯文本"), "纯文本");
+    assert.equal(expandDyEmojiShortcodes("[:c:]"), "![dy:c](/emoji/dy/c.png)");
+  });
+  it("正则含 g 标志（供分段渲染使用）", () => {
+    assert.ok(DY_EMOJI_RE.global);
+  });
+});