- execute <doc> — all blocks in document
- execute <doc> <section> — all blocks in subtree
- execute <doc> <section> <idx> — single block by index
- execute <doc> <section> <name> — block by #+NAME in section
- execute <doc> :<name> — named block anywhere in doc
Parser now extracts #+NAME: from block's affiliated keywords.
Supports bash, python, ruby, perl, and node interpreters.
Basic sandboxing via env_clear() and restricted PATH.