Refactor initialization: streamline log and config directory creation; enhance module exports in backend and UI widgets

src/backend/__init__.py

@@ -9,6 +9,7 @@ __all__ = [
     "NewEditionCheckerThread",
     "recreateElsaFile",
     "recreateFile",
+    "Catalogue"
 ]
 
 from .admin_console import AdminCommands
@@ -20,3 +21,4 @@ from .thread_bookgrabber import BookGrabber
 from .thread_neweditions import NewEditionCheckerThread
 from .threads_autoadder import AutoAdder
 from .threads_availchecker import AvailChecker
+from .catalogue import Catalogue