feat(i18n & ux): auditoria, traduccion completa, correcciones ux y gestion de idioma en perfil

app/routes/main.py

@@ -1,5 +1,6 @@
 from flask import Blueprint, render_template, jsonify, redirect, url_for, session, request, flash
 from flask_login import login_required, current_user
+from app import db
 from app.models.reservation import Reservation
 from app.models.classroom import Classroom
 from app.models.subject import Subject
@@ -124,4 +125,8 @@ def set_language(language=None):
         language = 'en'
     
     session['language'] = language
+    if current_user.is_authenticated:
+        current_user.preferred_language = language
+        db.session.commit()
+        
     return redirect(request.referrer or url_for('main.dashboard'))