chore: update output filename format

app.py

@@ -61,12 +61,18 @@ def process_files(file_objs, strength):
                     img = Image.open(file_path)
                     normal_map = process_image(img, strength)
                     
-                    out_name = f"normal_{file_name}"
-                    if not out_name.lower().endswith('.png'):
-                        out_name = os.path.splitext(out_name)[0] + '.png'
+                    base_name, ext = os.path.splitext(file_name)
+                    out_name = f"{base_name}_normalmap{ext}"
                         
                     out_path = os.path.join(temp_dir, out_name)
-                    normal_map.save(out_path, format="PNG")
+                    # Orijinal uzantıya göre kaydetmeye çalış, hata olursa PNG yap
+                    try:
+                        normal_map.save(out_path)
+                    except:
+                        out_name = f"{base_name}_normalmap.png"
+                        out_path = os.path.join(temp_dir, out_name)
+                        normal_map.save(out_path, format="PNG")
+                        
                     zipf.write(out_path, arcname=out_name)
                 except Exception as e:
                     print(f"Hata ({file_path}): {e}")