"feat: Update login template with new design"

backend/app/app.py

@@ -298,13 +298,14 @@ def login():
         # Daten je nach Anfrageart auslesen
         if is_json_request:
             data = request.get_json()
-            username = data.get("username")
+            username = data.get("username") or data.get("email")  # Fallback für email
             password = data.get("password")
             remember_me = data.get("remember_me", False)
         else:
-            username = request.form.get("username")
+            # Korrigierte Feldnamen - Template verwendet "email" nicht "username"
+            username = request.form.get("email")  # Geändert von "username" zu "email"
             password = request.form.get("password")
-            remember_me = request.form.get("remember-me") == "on"
+            remember_me = request.form.get("remember_me") == "on"  # Geändert von "remember-me"
         
         if not username or not password:
             error = "Benutzername und Passwort müssen angegeben werden."