get_or_fetch_zone_regulation no longer commits the shared /analyze transaction
mid-request on cache-miss. The upsert now runs in a fresh short-lived
SessionLocal() (commit/rollback/close), mirroring the zone_regulation_refresh
Celery task. Read-back still uses the shared session (READ COMMITTED sees the
committed row), so caller return shape is unchanged.
Resolves the #1850 item-4 SMELL (the outer analyze tx is designed to commit
exactly once via persist_analysis_run).
Refs #1850
Light1YT
7eee75f657