feat(web): árbol del plan de cuentas por ramas y con código con formato (planes segmentados)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

apps/web/src/app/features/masters/master-form.page.ts

@@ -130,7 +130,8 @@ export class MasterFormPage {
     return d['Frozen'] === 'tYES' ? { label: 'Inactivo', tone: 'muted' } : { label: 'Activo', tone: 'ok' };
   });
   protected readonly windowTitle = computed(() => {
-    const code = this.doc()?.[this.screen.keyField];
+    const d = this.doc();
+    const code = (this.screen.displayField && text(d?.[this.screen.displayField]).trim()) || d?.[this.screen.keyField];
     return code === undefined ? this.screen.singular : `${this.screen.singular} · ${text(code)}`;
   });