fix: trim whitespace from stdin password

When password is read from stdin (e.g. echo password | mark ...),
the trailing newline was included in the password string, causing
authentication to fail. Use strings.TrimSpace to strip it.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

util/auth.go

@@ -46,7 +46,7 @@ func GetCredentials(
 			)
 		}
 
-		password = string(stdin)
+		password = strings.TrimSpace(string(stdin))
 	}
 
 	if compileOnly && targetURL == "" {