Fix: Preservar alias al recargar lista de chats

El endpoint chats.get no retornaba el campo alias, lo que causaba
que al recargar los chats (cuando llega un mensaje nuevo) el alias
se perdiera.

Cambios:
- Agregar alias a la query de chats.get
- Priorizar alias sobre name en la respuesta
- Incluir originalName para referencia en el modal

server/api/messages/[instanceId]/chats.get.ts

@@ -8,6 +8,7 @@ interface ChatRow {
   id: string
   jid: string
   name: string | null
+  alias: string | null
   is_group: boolean
   unread_count: number
   last_message_at: Date | null
@@ -31,7 +32,7 @@ export default defineEventHandler(async (event) => {
 
   // Get chats with last message and type
   const result = await query<ChatRow>(
-    `SELECT c.id, c.jid, c.name, c.is_group, c.unread_count, c.last_message_at,
+    `SELECT c.id, c.jid, c.name, c.alias, c.is_group, c.unread_count, c.last_message_at,
        c.last_message_type,
        (SELECT COALESCE(content, caption) FROM messages m WHERE m.chat_id = c.id ORDER BY timestamp DESC LIMIT 1) as last_message
      FROM chats c
@@ -43,7 +44,11 @@ export default defineEventHandler(async (event) => {
   return result.rows.map(row => ({
     id: row.id,
     jid: row.jid,
-    name: row.name || row.jid.split('@')[0],
+    // Alias has priority over name
+    name: row.alias || row.name || row.jid.split('@')[0],
+    // Keep original name for reference
+    originalName: row.name || row.jid.split('@')[0],
+    alias: row.alias,
     isGroup: row.is_group,
     unreadCount: row.unread_count,
     lastMessageAt: row.last_message_at,