feat: reemplaza "Creado" por "Actualizado" en el listado de Proyectos

Columna con fecha y hora, orden por defecto (mas reciente primero) en
vez de fecha de creacion.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

frontend/src/i18n/messages.js

@@ -136,6 +136,7 @@ export const messages = {
     project_invite_email_hint: 'Si el correo no pertenece a nadie todavia, se le manda un enlace para que complete su registro y se una al proyecto.',
     project_invite_sent: 'Invitacion enviada por correo',
     project_created_at: 'Creado',
+    project_updated_at: 'Actualizado',
     project_deleted_at: 'Eliminado',
     project_filter_due_soon: 'Solo próximos a vencer (7 días)',
 
@@ -369,6 +370,7 @@ export const messages = {
     project_invite_email_hint: "If the email doesn't belong to anyone yet, they get a link to finish signing up and join the project.",
     project_invite_sent: 'Invite sent by email',
     project_created_at: 'Created',
+    project_updated_at: 'Updated',
     project_deleted_at: 'Deleted',
     project_filter_due_soon: 'Due soon only (7 days)',
 

frontend/src/pages/Proyectos/ProyectosPage.jsx

@@ -134,7 +134,7 @@ export default function ProyectosPage() {
     { key: 'owner_name', label: t('project_owner') },
     { key: 'progress_pct', label: t('project_progress'), render: (r) => <div style={{ width: 100 }}><ProgressBar value={Number(r.progress_pct)} /></div> },
     { key: 'risk_level', label: t('project_risk'), render: (r) => <Badge color={RISK_COLOR[r.risk_level]}>{t(`risk_${r.risk_level}`)}</Badge> },
-    { key: 'created_at', label: t('project_created_at'), render: (r) => String(r.created_at).slice(0, 10) },
+    { key: 'updated_at', label: t('project_updated_at'), render: (r) => String(r.updated_at).slice(0, 16) },
     ...(showTrash ? [{ key: 'deleted_at', label: t('project_deleted_at'), render: (r) => String(r.deleted_at).slice(0, 10) }] : []),
   ];
 
@@ -193,7 +193,7 @@ export default function ProyectosPage() {
         getSearchHaystack={(p) => `${p.code} ${p.name} ${p.owner_name} ${p.status_name}`}
         getRowKey={(p) => p.id}
         onRowClick={showTrash ? undefined : (p) => navigate(`/proyectos/${p.id}`)}
-        initialSort={{ key: 'created_at', dir: -1 }}
+        initialSort={{ key: 'updated_at', dir: -1 }}
         rowActions={
           showTrash
             ? (p) => [