feat(automod): render sticker, role & user names in moderation views

QoL lanjutan dari fix60084b3: content pesan mentah masih nampilin
snowflake (<@&roleid>, <@userid>, <:emoji:id>) di log moderasi dan
prompt LLM. Sekarang dirender ke nama yang bisa dibaca:

- Gateway capture: metadata menyimpan mentionedRoles + mentionedUsers
  (id+name) dari message.mentions, disimpan ke metadata JSON
- renderDiscordMentions(): <@&id> -> @RoleName, <@id> -> @Username,
  <:name:id> -> :name:, fallback @role/@user — dipakai di
  conversationContext (konteks LLM) dan moderationBuilders
  (getAnalysisContent) sehingga LLM lihat nama role/user beneran,
  bukan placeholder generik
- Frontend renderMessageContent() (mirror gateway) dipasang di semua
  tempat nampilin content: message-card, message-detail(-view),
  search-overlay, search-panel, users/channels section, live-stream,
  mod-queue, review list; sticker-only message tetap [Sticker: name],
  pesan teks+sticker kini ikut nampilin nama sticker
- tsc --noEmit PASS di gateway & frontend; renderDiscordMentions
  diverifikasi manual (6 kasus: role/user/emoji/unknown/plain)

services/frontend/src/app/(dashboard)/dashboard/page.tsx

@@ -31,6 +31,7 @@ export default function DashboardPage() {
     id: msg.id,
     content: msg.content || msg.id,
     username: msg.username,
+    metadata: msg.metadata ?? null,
     severity:
       msg.ai_severity && msg.ai_severity !== "none"
         ? (msg.ai_severity as ModQueueItem["severity"])

services/frontend/src/app/(dashboard)/messages/page.tsx

@@ -7,6 +7,7 @@ import { MessageList } from "@/components/messages/message-list";
 import { MessageDetailView } from "@/components/messages/message-detail-view";
 import { SearchOverlay } from "@/components/messages/search-overlay";
 import { extractFirstImage } from "@/components/messages/message-card";
+import { renderMessageContent } from "@/lib/format";
 import { SubNav } from "@/components/layout/sub-nav";
 import { ErrorState, LoadingSkeleton } from "@/components/shared";
 import { GlassCard } from "@/components/glass/card";
@@ -317,7 +318,7 @@ function ReviewList({
             <Flag className="mt-0.5 size-3.5 shrink-0 text-accent-purple" />
             <div className="min-w-0 flex-1">
               <p className="line-clamp-2 text-xs text-text-secondary">
-                {item.content || item.id}
+                {renderMessageContent(item.content, item.metadata) || item.id}
               </p>
             </div>
           </div>