Idempotent per-entity subfolder creation under the matching system
root. Fast-path SELECT short-circuits the common case. Inserts race
safely via uniq_document_folders_entity (partial unique on
port_id+entity_type+entity_id) — the loser re-SELECTs the winner's
row. Sibling-name collisions between two entities with the same
display name append (2), (3), … to the new folder; existing folders
never rename. Exports EntityType for use by downstream tasks.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Adds idempotent root-folder bootstrap (Clients/Companies/Yachts)
called on every port-init. ON CONFLICT DO NOTHING on the sibling-name
unique index prevents racing inserts; the re-SELECT returns the stable
row set in SYSTEM_ROOT_NAMES order. Same helper is invoked by the
backfill script in a later task.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
