feat(pipeline): dim_school/dim_location store GIAS codes; seed drift test

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

pipeline/transform/models/marts/dim_location.sql

@@ -32,4 +32,4 @@ select
     end as longitude
 from {{ ref('stg_gias_establishments') }} s
 -- Must match dim_school's status filter exactly (the API inner-joins the two).
-where s.status in ('Open', 'Open, but proposed to close')
+where s.status_code in (1, 3)