slight fix of the scanner

Web/app.py

@@ -4431,10 +4431,19 @@ def student_card_class_barcode_download():
         db = client[cfg.MONGODB_DB]
         student_cards = db['student_cards']
 
-        class_cards = list(student_cards.find({'Klasse': class_name}).sort('AusweisId', 1))
-        class_cards = [_decrypt_student_card_doc(card) for card in class_cards]
+        # 1. Alle Ausweise laden
+        all_cards = list(student_cards.find().sort('AusweisId', 1))
         client.close()
 
+        # 2. Alle entschlüsseln
+        decrypted_cards = [_decrypt_student_card_doc(card) for card in all_cards]
+        
+        # 3. Im Speicher nach der Klartext-Klasse filtern
+        class_cards = [
+            card for card in decrypted_cards 
+            if card.get('Klasse', '').strip() == class_name
+        ]
+
         if not class_cards:
             flash(f'Keine Ausweise für die Klasse "{class_name}" gefunden.', 'error')
             return redirect(url_for('student_cards_admin'))

Web/templates/library_table.html

@@ -816,12 +816,15 @@
 
         if (readerWrap) readerWrap.style.display = 'block';
         setScanStatus('Initializing camera...', 'warn');
+        
+        const scannerContainer = document.querySelector('.library-scan-reader-wrap');
+        scannerContainer.style.display = 'block';
 
         Quagga.init({
             inputStream: {
                 name: "Live",
                 type: "LiveStream",
-                target: document.querySelector('#library-scanner-container'),
+                target: document.querySelector('.library-scan-reader'),
                 constraints: {
                     width: 640,
                     height: 480,