fix: eurostat JSON-stat parsing + staging model corrections

Eurostat JSON-stat format (4-7 dimension sparse dict with 583K values)
causes DuckDB OOM — pre-process in extractor to flat records.
Also fix dim_cities unused CTE bug and playtomic venue lat/lon path.

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

transform/sqlmesh_padelnomics/models/foundation/dim_cities.sql

@@ -15,7 +15,8 @@ eurostat_cities AS (
     city_code,
     country_code,
     population,
-    ref_year
+    ref_year,
+    LOWER(REPLACE(city_code, country_code, ''))  AS city_slug_raw
   FROM staging.stg_population
   QUALIFY ROW_NUMBER() OVER (PARTITION BY city_code ORDER BY ref_year DESC) = 1
 ),
@@ -30,16 +31,6 @@ venue_counts AS (
   FROM foundation.dim_venues
   WHERE city IS NOT NULL AND city != ''
   GROUP BY country_code, city
-),
--- Eurostat city label mapping to canonical city names
--- (Eurostat uses codes like DE001C → Berlin; we keep both)
-eurostat_labels AS (
-  SELECT DISTINCT
-    city_code,
-    country_code,
-    -- Derive a slug-friendly city name from the code as fallback
-    LOWER(REPLACE(city_code, country_code, ''))  AS city_slug_raw
-  FROM eurostat_cities
 )
 SELECT
   ec.city_code,

transform/sqlmesh_padelnomics/models/staging/stg_playtomic_venues.sql

@@ -19,8 +19,8 @@ WITH parsed AS (
     tenant -> 'address' ->> 'city'                        AS city,
     tenant -> 'address' ->> 'postal_code'                 AS postal_code,
     tenant -> 'address' ->> 'country_code'                AS country_code,
-    TRY_CAST(tenant -> 'address' ->> 'coordinate_lat' AS DOUBLE) AS lat,
-    TRY_CAST(tenant -> 'address' ->> 'coordinate_lon' AS DOUBLE) AS lon,
+    TRY_CAST(tenant -> 'address' -> 'coordinate' ->> 'lat' AS DOUBLE) AS lat,
+    TRY_CAST(tenant -> 'address' -> 'coordinate' ->> 'lon' AS DOUBLE) AS lon,
     tenant ->> 'sport_ids'                                AS sport_ids_raw,
     tenant ->> 'tenant_type'                              AS tenant_type,
     filename                                              AS source_file,

transform/sqlmesh_padelnomics/models/staging/stg_population.sql

@@ -1,5 +1,5 @@
 -- Eurostat Urban Audit city population (dataset: urb_cpop1).
--- Reads landing zone JSON directly and parses the Eurostat multidimensional format.
+-- Reads pre-processed landing zone JSON (extractor normalizes JSON-stat to flat rows).
 -- One row per (city_code, year) with validated population values.
 --
 -- Source: data/landing/eurostat/{year}/{month}/urb_cpop1.json.gz
@@ -11,51 +11,26 @@ MODEL (
   grain (city_code, ref_year)
 );
 
-WITH raw AS (
-  SELECT raw_json, filename
-  FROM read_json(
-    @LANDING_DIR || '/eurostat/*/*/urb_cpop1.json.gz',
-    format = 'auto',
-    filename = true,
-    columns = { 'raw_json': 'JSON' }
-  )
-),
-cities AS (
+WITH parsed AS (
   SELECT
-    city_code,
-    (city_pos)::INTEGER AS city_pos,
-    filename, raw_json,
-    (json_extract(raw_json, '$.size[1]'))::INTEGER AS n_times
-  FROM raw,
-  LATERAL (
-    SELECT key AS city_code, value::INTEGER AS city_pos
-    FROM json_each(json_extract(raw_json, '$.dimension.cities.category.index'))
+    row ->> 'geo_code'           AS geo_code,
+    row ->> 'ref_year'           AS ref_year,
+    TRY_CAST(row ->> 'value' AS DOUBLE) AS population,
+    filename                     AS source_file,
+    CURRENT_DATE                 AS extracted_date
+  FROM (
+    SELECT UNNEST(rows) AS row, filename
+    FROM read_json(
+      @LANDING_DIR || '/eurostat/*/*/urb_cpop1.json.gz',
+      format = 'auto',
+      filename = true
+    )
   )
-),
-times AS (
-  SELECT key AS ref_year, value::INTEGER AS time_pos
-  FROM (SELECT raw_json FROM raw LIMIT 1),
-  LATERAL (
-    SELECT key, value
-    FROM json_each(json_extract(raw_json, '$.dimension.time.category.index'))
-  )
-),
-parsed AS (
-  SELECT
-    c.city_code,
-    t.ref_year,
-    TRY_CAST(
-      json_extract(c.raw_json, '$.' || (c.city_pos * c.n_times + t.time_pos)::TEXT)
-      AS DOUBLE
-    ) AS population,
-    c.filename AS source_file,
-    CURRENT_DATE AS extracted_date
-  FROM cities c
-  CROSS JOIN times t
+  WHERE (row ->> 'geo_code') IS NOT NULL
 )
 SELECT
-  UPPER(city_code)               AS city_code,
-  UPPER(LEFT(city_code, 2))      AS country_code,
+  UPPER(geo_code)                AS city_code,
+  UPPER(LEFT(geo_code, 2))       AS country_code,
   ref_year::INTEGER              AS ref_year,
   population::BIGINT             AS population,
   extracted_date