feat: panel de Actualizaciones en Configuracion (solo informativo)

Compara la version instalada contra el CHANGELOG.md de main en Gitea (lectura anonima por HTTPS,
sin token) y muestra cada version pendiente con su criticidad -- derivada del digito que cambio
(1ro=Alta, 2do=Media, 3ro=Baja, sin etiquetar nada a mano, regla ya documentada en
VERSIONADO.md), una descripcion breve, y si trae migraciones de base de datos nuevas. Banner en
rojo avisando que la actualizacion requiere reiniciar el sistema.

No instala nada automaticamente -- solo informa. Aplicar la actualizacion (git pull, build,
migrar, reiniciar servicios) sigue siendo manual, a criterio del administrador de cada
instalacion, tal cual DEPLOY_WEB.md ya documenta.

Nuevo GET /api/updater/status (solo superadmin). Requiere que el repo en Gitea sea publico con
vista anonima habilitada -- documentado en DEPLOY_WEB.md.

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

frontend/src/pages/Configuracion/ConfiguracionPage.jsx

@@ -1,5 +1,5 @@
 import { Navigate } from 'react-router-dom';
-import { Palette, ListChecks, Flag, FolderKanban, Layers, Mail, Building2 } from 'lucide-react';
+import { Palette, ListChecks, Flag, FolderKanban, Layers, Mail, Building2, RefreshCw } from 'lucide-react';
 import { useUi } from '../../context/ui-context.jsx';
 import { useAuth } from '../../context/auth-context.jsx';
 import { Expander } from '../../components/Expander.jsx';
@@ -8,6 +8,7 @@ import { ComboBox } from '../../components/ComboBox.jsx';
 import { CatalogEditor } from './CatalogEditor.jsx';
 import SmtpSettingsPanel from './SmtpSettingsPanel.jsx';
 import CompanySettingsPanel from './CompanySettingsPanel.jsx';
+import UpdaterPanel from './UpdaterPanel.jsx';
 
 export default function ConfiguracionPage() {
   const { t, theme, setTheme, lang, setLang, buttonMode, setButtonMode } = useUi();
@@ -101,6 +102,10 @@ export default function ConfiguracionPage() {
       <Expander icon={Mail} title={t('config_smtp')}>
         <SmtpSettingsPanel />
       </Expander>
+
+      <Expander icon={RefreshCw} title={t('config_updater')}>
+        <UpdaterPanel />
+      </Expander>
     </div>
   );
 }

frontend/src/pages/Configuracion/UpdaterPanel.jsx

@@ -0,0 +1,61 @@
+import { RefreshCw } from 'lucide-react';
+import { useUi } from '../../context/ui-context.jsx';
+import { useAsync } from '../../hooks/useAsync.js';
+import { getUpdateStatus } from '../../services/updater.js';
+import { Button } from '../../components/Button.jsx';
+import { Badge } from '../../components/Badge.jsx';
+import { InfoBar } from '../../components/InfoBar.jsx';
+
+const CRITICALITY_COLOR = { alta: 'danger', media: 'warning', baja: 'success' };
+
+export default function UpdaterPanel() {
+  const { t } = useUi();
+  const { data: status, loading, error, reload } = useAsync(getUpdateStatus, []);
+
+  return (
+    <div>
+      <div style={{ display: 'flex', alignItems: 'center', gap: 10, marginBottom: 12 }}>
+        <Button variant="standard" icon={RefreshCw} onClick={reload} disabled={loading}>
+          {t('updater_check')}
+        </Button>
+        {status && <span className="text-muted" style={{ fontSize: '.78rem' }}>{t('updater_current_version')} v{status.currentVersion}</span>}
+      </div>
+
+      {loading && <div className="text-muted">{t('common_loading')}</div>}
+      {error && <InfoBar tone="error" dismissible={false}>{error}</InfoBar>}
+
+      {status && status.upToDate && (
+        <InfoBar tone="success" dismissible={false}>{t('updater_up_to_date')}</InfoBar>
+      )}
+
+      {status && !status.upToDate && (
+        <div>
+          <InfoBar tone="error" dismissible={false}>{t('updater_restart_required')}</InfoBar>
+          {status.hasMigrations && (
+            <InfoBar tone="warning" dismissible={false}>{t('updater_has_migrations')}</InfoBar>
+          )}
+
+          <div className="panel-card">
+            <h4 style={{ marginTop: 0 }}>
+              {t('updater_available')} — v{status.currentVersion} → v{status.latestVersion}
+              {' '}
+              <Badge color={CRITICALITY_COLOR[status.overallCriticality]}>{t(`updater_criticality_${status.overallCriticality}`)}</Badge>
+            </h4>
+            {status.pending.map((entry) => (
+              <div key={entry.version} style={{ padding: '10px 0', borderTop: '1px solid rgb(var(--line))' }}>
+                <div style={{ display: 'flex', alignItems: 'center', gap: 8, marginBottom: 4 }}>
+                  <strong>v{entry.version}</strong>
+                  <span className="text-muted" style={{ fontSize: '.72rem' }}>{entry.date}</span>
+                  <Badge color={CRITICALITY_COLOR[entry.criticality]}>{t(`updater_criticality_${entry.criticality}`)}</Badge>
+                </div>
+                <div style={{ fontSize: '.8rem', color: 'rgb(var(--muted))' }}>{entry.summary}</div>
+              </div>
+            ))}
+          </div>
+
+          <div className="text-muted" style={{ fontSize: '.76rem' }}>{t('updater_rollback_hint')}</div>
+        </div>
+      )}
+    </div>
+  );
+}