feat(api): fix lint

app/routes/main.py

@@ -1,4 +1,4 @@
-from flask import Blueprint, render_template, jsonify
+from flask import Blueprint, render_template, jsonify, redirect, url_for, session, request
 from flask_login import login_required, current_user
 from app.models.reservation import Reservation
 from app.models.classroom import Classroom
@@ -6,6 +6,7 @@ from app.models.subject import Subject
 from app.models.subject import Commission
 from datetime import datetime, timedelta
 from sqlalchemy import func
+from flask_babel import gettext as _
 
 main_bp = Blueprint('main', __name__)
 
@@ -105,4 +106,12 @@ def dashboard_stats_api():
         'today_reservations': today_reservations,
         'week_reservations': week_reservations,
         'monthly_data': list(reversed(monthly_data))
-    })
+    })
+
+@main_bp.route('/set_language/<language>')
+def set_language(language=None):
+    if language not in ['en', 'es']:
+        language = 'en'
+    
+    session['language'] = language
+    return redirect(request.referrer or url_for('main.dashboard'))