core&ui: add discussion history (#450)

Co-authored-by: 无限UCW <45730483+wuxianucw@users.noreply.github.com>
Co-authored-by: undefined <i@undefined.moe>

packages/ui-default/index.ts

@@ -254,4 +254,10 @@ export function apply(ctx: Context) {
   ctx.on('system/setting', () => triggerHotUpdate());
   ctx.on('app/watch/change', triggerHotUpdate);
   ctx.on('app/watch/unlink', triggerHotUpdate);
+  ctx.on('handler/after/DiscussionRaw', async (that) => {
+    if (that.args.render && that.response.type === 'text/markdown') {
+      that.response.type = 'text/html';
+      that.response.body = await markdown.render(that.response.body);
+    }
+  });
 }