Reads ONE patient's chart-review subtree from the source database (db), parent → child, and
validates it. Read-only. Throws if the patient is missing or has no entity. A patient with
charts but no treatment_episode clones with a warning: patient-scoped runs fetch charts
unfiltered, and an episode-scoped run can't be requested without an episode id to pass.
Reads ONE patient's chart-review subtree from the source database (
db), parent → child, and validates it. Read-only. Throws if the patient is missing or has no entity. A patient with charts but no treatment_episode clones with a warning: patient-scoped runs fetch charts unfiltered, and an episode-scoped run can't be requested without an episode id to pass.