feat(gias): load UKPRN and the inspectorate GIAS names (H4)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

pipeline/transform/models/staging/stg_gias_establishments.sql

@@ -38,6 +38,7 @@ renamed as (
         "UrbanRural (name)"                             as urban_rural,
         "ParliamentaryConstituency (name)"              as parliamentary_constituency,
         "NurseryProvision (name)"                       as nursery_provision,
+        nullif(trim("InspectorateName (name)"), '')     as inspectorate_name,
         cast(nullif("Easting", '') as integer)          as easting,
         cast(nullif("Northing", '') as integer)         as northing,
         cast(nullif("StatutoryLowAge", '') as integer)  as statutory_low_age,

pipeline/transform/models/staging/stg_gias_ukprn.sql

@@ -0,0 +1,11 @@
+-- URN → UKPRN from the raw GIAS extract, for matching Ofsted's further
+-- education providers (int_ofsted_fe_latest, int_ofsted_listed; audit H4).
+-- A model on the raw source rather than a column of stg_gias_establishments:
+-- a ref to that model would put the Ofsted models into the daily build's
+-- stg_gias_establishments+ selection (pipeline/tests/test_dag_selectors.py).
+
+select
+    cast("URN" as integer)          as urn,
+    nullif(trim("UKPRN"), '')       as ukprn
+from {{ source('raw', 'gias_establishments') }}
+where "URN" ~ '^[0-9]+$'