Run library, checks and downloads in background threads with parallel fetching

GOGUpdater.py

@@ -12,10 +12,33 @@ from src.constants import APP_TITLE
 from src.ui.main_window import MainWindow
 
 
+def _setup_logging(config_dir) -> None:
+    """Log DEBUG to stderr and to a rotating file for diagnostics."""
+    log_file = config_dir / "gogupdater.log"
+    logger.add(
+        log_file,
+        level="DEBUG",
+        rotation="2 MB",
+        retention=3,
+        backtrace=True,
+        diagnose=True,
+        enqueue=True,  # thread-safe logging from worker threads
+    )
+    logger.info(f"Logging to {log_file}")
+
+    # Make sure exceptions raised inside Qt slots are logged instead of swallowed.
+    def _excepthook(exc_type, exc_value, exc_tb):
+        logger.opt(exception=(exc_type, exc_value, exc_tb)).error("Uncaught exception")
+        sys.__excepthook__(exc_type, exc_value, exc_tb)
+
+    sys.excepthook = _excepthook
+
+
 def main() -> None:
     config_dir = DEFAULT_CONFIG_DIR
     config_dir.mkdir(parents=True, exist_ok=True)
 
+    _setup_logging(config_dir)
     logger.info(f"Starting {APP_TITLE}")
 
     auth = AuthManager(config_dir)