pub fn xdg_config_dir() -> SshCliResult<PathBuf>Expand description
Resolves the XDG config directory for crate::constants::APP_NAME.
Uses directories::ProjectDirs (Linux: $XDG_CONFIG_HOME/ssh-cli or
~/.config/ssh-cli). Does not honor SSH_CLI_HOME or --config-dir
— callers layer those overrides themselves.
§Errors
Returns SshCliError::XdgDirectory when the home/config root cannot be
determined (rare headless environments) — G-ERR-03.