Customer-facing API reference for the three modules, written from source
plus the live test-script job. Scoped to the API: the signals.yml and
schedule.yaml contract gets only what a caller needs to read the API
correctly, not a full treatment.
Three behaviours documented because they are invisible from the source a
customer reads: a write batch is all-or-nothing on an unknown id, run()
skips logic_func entirely on a failed or empty read, and every method
swallows its exceptions so a falsy return conflates failure with empty.
The dbutils calls also set no timeout, unlike the signal calls.
pyproject.toml is unchanged; README.md is already its readme field.
Iñigo Etxaniz