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/lib/format.ts

@@ -1,3 +1,5 @@
+import type { MessageMetadata } from "@/lib/types/message";
+
 /**
  * Format a number with locale separators.
  */
@@ -72,3 +74,65 @@ export function getMessageChannelLabel(msg: {
   if (channelName) return channelName;
   return msg.channel_id?.slice(0, 8) ?? "";
 }
+
+/**
+ * Render Discord mention/emoji/sticker tokens in message content to readable
+ * names using the captured metadata (mentionedRoles / mentionedUsers /
+ * customEmojis / stickers). Mirror of the gateway's renderDiscordMentions.
+ *
+ * - `<@&id>`           → `@RoleName` (falls back to `@role`)
+ * - `<@id>` / `<@!id>` → `@Username` (falls back to `@user`)
+ * - `<:name:id>`       → `:name:`    (falls back to the literal name)
+ * - sticker-only content already stored as `[Sticker: name]`; when a message
+ *   has both text and stickers, append `[Sticker: name]` so stickers always
+ *   surface in the feed.
+ */
+export function renderMessageContent(
+  content: string,
+  metadata?: string | null,
+): string {
+  if (!content) return content;
+  let m: MessageMetadata | null = null;
+  try {
+    m = JSON.parse(metadata ?? "") as MessageMetadata;
+  } catch {
+    // metadata malformed — render tokens from their literal names only
+  }
+
+  let rendered = content;
+  if (rendered.includes("<")) {
+    const roles = new Map(
+      (m?.mentionedRoles ?? []).map((r) => [r.id, r.name] as const),
+    );
+    const users = new Map(
+      (m?.mentionedUsers ?? []).map((u) => [u.id, u.username] as const),
+    );
+    const emojis = new Map(
+      (m?.customEmojis ?? []).map((e) => [e.id, e.name] as const),
+    );
+    rendered = rendered.replace(
+      /<(?:a)?:([a-zA-Z0-9_]+):(\d{17,20})>|<@!?(\d{17,20})>|<@&(\d{17,20})>/g,
+      (_full, emojiTokenName, emojiId, userId, roleId) => {
+        if (emojiId !== undefined) {
+          return `:${emojis.get(emojiId) ?? emojiTokenName}:`;
+        }
+        if (roleId !== undefined) return `@${roles.get(roleId) ?? "role"}`;
+        if (userId !== undefined) return `@${users.get(userId) ?? "user"}`;
+        return _full;
+      },
+    );
+  }
+
+  const stickers = m?.stickers ?? [];
+  if (
+    stickers.length > 0 &&
+    !rendered.includes("[Sticker:") &&
+    !rendered.includes("[Attachment:")
+  ) {
+    rendered += ` ${stickers
+      .map((s) => `[Sticker: ${s.name ?? "unknown"}]`)
+      .join(" ")}`;
+  }
+
+  return rendered;
+}

services/frontend/src/lib/types/message.ts

@@ -43,6 +43,23 @@ export interface StickerInfo {
   url?: string | null;
 }
 
+export interface CustomEmojiInfo {
+  id: string;
+  name: string;
+  animated?: boolean;
+  url?: string | null;
+}
+
+export interface MentionedRoleInfo {
+  id: string;
+  name: string;
+}
+
+export interface MentionedUserInfo {
+  id: string;
+  username: string;
+}
+
 export interface AttachmentRef {
   name: string;
   url: string;
@@ -70,6 +87,9 @@ export interface MessageMetadata {
   stickers?: StickerInfo[] | null;
   attachments?: AttachmentRef[] | null;
   embeds?: EmbedInfo[] | null;
+  customEmojis?: CustomEmojiInfo[] | null;
+  mentionedRoles?: MentionedRoleInfo[] | null;
+  mentionedUsers?: MentionedUserInfo[] | null;
   channel?: ChannelRef | null;
   reference?: ReferenceInfo | null;
 }