fix(tap-gias): declare numeric CSV columns as StringType

CSV is read with dtype=str so all values arrive as strings. Declaring
LA (code) and EstablishmentNumber as IntegerType caused schema
validation failures in target-postgres. Use StringType for all columns
except URN (which is explicitly cast to int for the primary key).
Type casting happens in dbt staging models.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pipeline/plugins/extractors/tap-uk-gias/tap_uk_gias/tap.py

@@ -26,14 +26,16 @@ class GIASEstablishmentsStream(Stream):
     replication_key = None
 
     # Schema is wide (~250 columns); we declare key columns and pass through the rest
+    # All columns are read as strings from CSV; dbt staging models handle type casting.
+    # Only URN is cast to int in get_records() for the primary key.
     schema = th.PropertiesList(
         th.Property("URN", th.IntegerType, required=True),
         th.Property("EstablishmentName", th.StringType),
         th.Property("TypeOfEstablishment (name)", th.StringType),
         th.Property("PhaseOfEducation (name)", th.StringType),
-        th.Property("LA (code)", th.IntegerType),
+        th.Property("LA (code)", th.StringType),
         th.Property("LA (name)", th.StringType),
-        th.Property("EstablishmentNumber", th.IntegerType),
+        th.Property("EstablishmentNumber", th.StringType),
         th.Property("EstablishmentStatus (name)", th.StringType),
         th.Property("Postcode", th.StringType),
     ).to_dict()