feat: version 2.1.0 -- logo de marca separado en barra lateral

El logo de empresa (Configuracion > Empresa) ahora va en un espacio
nuevo arriba de la barra lateral, solo visible si esta configurado.
El logo de LinkedCorp de abajo deja de ser configurable: identifica
siempre al desarrollador del sistema, sin importar que empresa lo use.

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

frontend/src/components/NavigationView.jsx

@@ -26,6 +26,15 @@ export function NavigationView({ mode }) {
   const brandName = branding.name || t('appName');
   return (
     <nav className={`nav-view ${mode}`}>
+      {branding.logoUrl && (
+        <div className="nav-header">
+          <img
+            src={branding.logoUrl}
+            alt={brandName}
+            className={compact ? 'nav-logo-icon-header' : 'nav-logo-full-header'}
+          />
+        </div>
+      )}
       <div className="nav-items">
         {items.map((item) => (
           <NavLink key={item.to} to={item.to} end={item.end} className={({ isActive }) => `nav-item ${isActive ? 'active' : ''}`}>
@@ -36,10 +45,10 @@ export function NavigationView({ mode }) {
       </div>
       <div className="nav-footer">
         {compact ? (
-          <img src={branding.logoUrl || logoIcon} alt={brandName} className="nav-logo-icon-footer" />
+          <img src={logoIcon} alt="LinkedCorp" className="nav-logo-icon-footer" />
         ) : (
           <>
-            <img src={branding.logoUrl || (theme === 'light' ? logoLight : logoDark)} alt={brandName} className="nav-logo-full-footer" />
+            <img src={theme === 'light' ? logoLight : logoDark} alt="LinkedCorp" className="nav-logo-full-footer" />
             <span className="nav-version">v{pkg.version}</span>
           </>
         )}