feat: version 2.17.1 -- Proyectos: checkbox "Ocultar proyectos 100%"

Desmarcado por defecto; la eleccion se guarda en localStorage y sobrevive al
cierre de sesion.

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

frontend/src/i18n/messages.js

@@ -186,6 +186,7 @@ export const messages = {
     project_updated_at: 'Actualizado',
     project_deleted_at: 'Eliminado',
     project_filter_due_soon: 'Solo próximos a vencer (7 días)',
+    project_filter_hide_completed: 'Ocultar proyectos 100%',
 
     nav_recurring_tasks: 'Tareas recurrentes',
     nav_notes: 'Notas',
@@ -668,6 +669,7 @@ export const messages = {
     project_updated_at: 'Updated',
     project_deleted_at: 'Deleted',
     project_filter_due_soon: 'Due soon only (7 days)',
+    project_filter_hide_completed: 'Hide 100% projects',
 
     nav_recurring_tasks: 'Recurring tasks',
     nav_notes: 'Notes',