use admin linked user as comment author so avatar and name are correct

packages/api/src/routes/comments.ts

@@ -157,11 +157,19 @@ export default async function commentRoutes(app: FastifyInstance) {
 
       const cleanBody = body.body.replace(INVISIBLE_RE, '');
       const isAdmin = !!req.adminId;
+
+      // use admin's linked user as author when commenting as admin
+      let commentAuthorId = req.user!.id;
+      if (isAdmin) {
+        const adminUser = await prisma.adminUser.findUnique({ where: { id: req.adminId! }, select: { linkedUserId: true } });
+        if (adminUser?.linkedUserId) commentAuthorId = adminUser.linkedUserId;
+      }
+
       const comment = await prisma.comment.create({
         data: {
           body: cleanBody,
           postId: post.id,
-          authorId: req.user!.id,
+          authorId: commentAuthorId,
           replyToId: body.replyToId ?? null,
           isAdmin,
           adminUserId: req.adminId ?? null,