Load functional use categories

Returns a tibble of functional use categories from ComptoxR with provenance tracking. Falls back gracefully if ComptoxR is unavailable or API fails.

Usage

load_functional_categories(cache_dir)

Arguments

cache_dir

Directory for cache files (e.g., "data/reference_cache")

Value

Tibble with columns: term, source, active

Details

NOTE: Cache format changed in Phase 13 - delete existing cache files if needed.