wip(corpus): dbt package output, dbt-snowflake DML and unaliased names on main e9f002d

Round 3 adds 76 queries: dbt_utils and dbt_date macros compiled by
dbt-snowflake 1.12 (date_spine, get_date_dimension, pivot,
generate_surrogate_key, deduplicate, cross-database macros, generic tests),
dbt-snowflake's rendered snapshot SQL and incremental DML (merge with
incremental predicates, delete+insert, insert_overwrite, snapshot merge),
FLATTEN over VARIANT, and unaliased output names ahead of #99. Database and
schema qualifiers are dropped; ORDERS_SNAPSHOT joins the model schema.

Author: kvlonge