Remove unused imports and clean up code structure across multiple files

src/backend/semester.py

@@ -6,7 +6,7 @@ from loguru import logger as log
 
 logger = log
 logger.remove()
-logger.add("logs/application.log", rotation="1 week", enqueue=True)
+logger.add("logs/application.log", rotation="1 week", retention="1 month", enqueue=True)
 
 
 # logger.add(sys.stderr, format="{time} {level} {message}", level="INFO")