Fixes Pylance type error - create_engine() expects str, not str | None.
Using direct access raises KeyError if not set, which is correct behavior.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
dbt creates mart tables in public_marts schema, not public.
Updated all notebook SQL queries to use the correct schema.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>