feat(guild): translate <@user.name:NAME> -> <@userId>

Before persist/parse, resolve <@user.name:NAME> (outside backticks) via
Center and rewrite to <@userId>; unresolved tokens left as-is. Translated
ids then flow into the existing mention/wakeup/sub-frame logic.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/messaging/messaging.controller.ts

@@ -18,7 +18,8 @@ import { Message } from '../entities/message.entity';
 import { IdempotencyRecord } from '../entities/idempotency-record.entity';
 import { WakeMapping } from '../entities/wake-mapping.entity';
 import { parseSlashCommand } from '../channels/slash-commands';
-import { parseMentions } from '../channels/mentions';
+import { parseMentions, extractNameMentions, replaceNameMentions } from '../channels/mentions';
+import { resolveUserNames } from '../common/center-auth';
 import { TurnService } from '../channels/turn.service';
 import { EventsService } from '../events/events.service';
 import { clampLimit, computeNextExpectedSeq } from './pagination.util';
@@ -146,8 +147,17 @@ export class MessagingController {
     const isRotating = xType === 'discuss' || xType === 'work';
     const authorUserId = String(body.authorUserId ?? 'anonymous');
 
+    // ---- translate <@user.name:NAME> -> <@userId> (outside backticks) via
+    // Center before anything else persists/parses the content
+    let content = body.content ?? '';
+    const names = extractNameMentions(content);
+    if (names.length) {
+      const map = await resolveUserNames(names);
+      content = replaceNameMentions(content, map);
+    }
+
     // ---- command interception: registered slash commands are never delivered
-    const cmd = parseSlashCommand(body.content ?? '');
+    const cmd = parseSlashCommand(content);
     if (cmd) {
       if (isRotating && cmd.name === 'no-reply') {
         const { ack } = await this.turn.onNoReply(channelId, authorUserId);
@@ -163,7 +173,7 @@ export class MessagingController {
     // ---- normal message
     const message = await this.persistMessage(channelId, {
       authorUserId,
-      content: body.content,
+      content,
       clientMessageId: body.clientMessageId,
       replyToMessageId: body.replyToMessageId,
       mentions: body.mentions,
@@ -180,8 +190,8 @@ export class MessagingController {
       data: responseBody,
     });
 
-    // mentions: <@id> outside backtick spans
-    const mentionIds = parseMentions(body.content ?? '');
+    // mentions: <@id> outside backtick spans (post name-translation)
+    const mentionIds = parseMentions(content);
 
     if (isRotating) {
       // discuss/work: rotation (incl. mention sub-frames) picks the target