Function templates_path_from 

pub fn templates_path_from(
    xdg_config_home: Option<&str>,
    home: Option<&str>,
    appdata: Option<&str>,
    is_windows: bool,
) -> Option<PathBuf>

Derive bhtune’s default user template catalog location the same way config_path_from derives bhtune.toml’s – deliberately the same directory, since both are per-user settings a site admin edits by hand, not persistent application data (contrast default_db_path_from/default_log_dir_from, which live under the platform data directory instead). See load_user_templates for how this default fits into the full template-user-catalog precedence chain.

• Windows (is_windows = true): %APPDATA%\bhtune\templates.toml.
• Elsewhere: $XDG_CONFIG_HOME/bhtune/templates.toml, falling back to $HOME/.config/bhtune/templates.toml.