Function is_programming_language 

pub fn is_programming_language(path: &Path) -> bool

Check if a path is a programming language (not a data/config format).

Returns false for data formats like JSON, YAML, TOML, Markdown, etc. even though normalize-languages can parse them for syntax highlighting.

Useful for architecture analysis where only “code” files are relevant. Uses normalize_language_meta::capabilities_for() to determine if a language is executable code.