Introduction of the images to the detailed view to the library_table.html

Web/app.py

@@ -466,16 +466,36 @@ PERMISSION_ACTION_ENDPOINTS = {
 }
 
 ALLOWED_COVER_DOMAINS = {
+    # --- Google / Open APIs ---
     "books.google.com",
-    "covers.openlibrary.org",
-    "images-na.ssl-images-amazon.com",
-    "m.media-amazon.com",
-    "www.isbn.de",
+    "www.googleapis.com",
+
+    # --- Open Library / Internet Archive ---
     "covers.openlibrary.org",
     "openlibrary.org",
+
+    # --- Amazon / Goodreads ---
+    "images-na.ssl-images-amazon.com",
+    "m.media-amazon.com",
+    "i.gr-assets.com",            # Goodreads image CDN
+
+    # --- Library / Catalog Services ---
+    "www.isbn.de",
     "lobid.org",
-    "www.googleapis.com",
-    "www.westermann.de"
+    "syndetics.com",              # Standard cover provider for libraries
+    "pics.librarything.com",      # LibraryThing covers
+    "portal.dnb.de",              # Deutsche Nationalbibliothek
+
+    # --- German Educational & International Publishers ---
+    "www.westermann.de",
+    "www.klett.de",               # Ernst Klett Verlag
+    "medien.klett.de",            # Klett media CDN
+    "www.cornelsen.de",           # Cornelsen Verlag
+    "images.penguinrandomhouse.com", # Penguin Random House
+
+    # --- Book Retailer CDNs (often used for cover fetching) ---
+    "images.thalia.media",        # Thalia
+    "bilder.buecher.de"           # buecher.de
 }
 
 SENSITIVE_AUDIT_FIELDS = ["email", "username", "full_name", "phone", "borrower", "ip"]
@@ -10044,7 +10064,7 @@ def download_book_cover():
             return jsonify({"error": "Only public HTTPS URLs are allowed"}), 400
 
         # 2. SSRF Protection: Strict Allowlist Check
-        # if parsed_url.netloc not in ALLOWED_COVER_DOMAINS:  # ---------------------------------------------- has to be implementet at a laterstage ---------------------------------------------------------------
+        # if parsed_url.netloc not in ALLOWED_COVER_DOMAINS:
         #    return jsonify({"error": "Target host is not an allowed book cover provider"}), 403
         
         # Download the image (allow_redirects=False prevents redirecting to internal IPs)