keep browser open on failed login

downloader.py

@@ -239,7 +239,12 @@ def download_all_invoices() -> list[Path]:
         page = context.pages[0] if context.pages else context.new_page()
         page.set_default_timeout(Config.BROWSER_TIMEOUT)
 
+        try:
             page = login(context, page)
+        except Exception:
+            logger.exception("Login failed. Browser will remain open for inspection.")
+            input("Login failed. Inspect the browser, then press Enter to close it...")
+            raise
 
         page = _goto_with_retry(context, page, BILLING_URL)