feat(transform): add country_name_en + country_slug to dim_cities, pass through city_market_profile

Prerequisite for all pSEO serving models. Adds CASE-based country_name_en
and URL-safe country_slug to foundation.dim_cities, then selects them through
serving.city_market_profile so downstream models inherit them automatically.

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

transform/sqlmesh_padelnomics/models/serving/city_market_profile.sql

@@ -17,6 +17,8 @@ WITH base AS (
   SELECT
     c.city_code,
     c.country_code,
+    c.country_name_en,
+    c.country_slug,
     c.city_name,
     c.city_slug,
     c.lat,
@@ -55,6 +57,8 @@ scored AS (
 SELECT
   s.city_code,
   s.country_code,
+  s.country_name_en,
+  s.country_slug,
   s.city_name,
   s.city_slug,
   s.lat,