refactor: align transform layer with template methodology

Three deviations from the quart_saas_boilerplate methodology corrected:

1. Fix dim_cities LIKE join (data quality bug)
   - Old: FROM eurostat_cities LEFT JOIN venue_counts LIKE '%country_code%'
     → cartesian product (2.6M rows vs ~5500 expected)
   - New: FROM venue_cities (dim_venues) as primary table, Eurostat for
     enrichment only. grain (country_code, city_slug).
   - Also fixes REGEXP_REPLACE to LOWER() before regex so uppercase city
     names aren't stripped to '-'

2. Rename fct_venue_capacity → dim_venue_capacity
   - Static venue attributes with no time key are a dimension, not a fact
   - No SQL logic changes; update fct_daily_availability reference

3. Add fct_availability_slot at event grain
   - New: grain (snapshot_date, tenant_id, resource_id, slot_start_time)
   - Recheck dedup logic moves here from fct_daily_availability
   - fct_daily_availability now reads fct_availability_slot (cleaner DAG)

Downstream fixes:
- city_market_profile, planner_defaults grain → (country_code, city_slug)
- pseo_city_costs_de, pseo_city_pricing add city_key composite natural key
  (country_slug || '-' || city_slug) to avoid URL collisions across countries
- planner_defaults join in pseo_city_costs_de uses both country_code + city_slug
- Templates updated: natural_key city_slug → city_key

Added transform/sqlmesh_padelnomics/CLAUDE.md documenting data modeling rules,
conformed dimension map, and source integration architecture.

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

transform/sqlmesh_padelnomics/models/foundation/dim_venue_capacity.sql

@@ -0,0 +1,47 @@
+-- Venue capacity: total bookable court-hours per day and week.
+-- Derived from active court count × opening hours.
+-- Used as the denominator for occupancy rate in fct_daily_availability.
+--
+-- One row per venue (Playtomic tenant).
+-- Named dim_* because these are static venue attributes with no time key,
+-- not events or measurements.
+
+MODEL (
+  name foundation.dim_venue_capacity,
+  kind FULL,
+  cron '@daily',
+  grain tenant_id
+);
+
+WITH weekly_hours AS (
+  SELECT
+    tenant_id,
+    SUM(hours_open)                               AS hours_open_per_week,
+    AVG(hours_open)                               AS avg_hours_open_per_day,
+    COUNT(*)                                      AS days_open_per_week
+  FROM staging.stg_playtomic_opening_hours
+  GROUP BY tenant_id
+),
+court_counts AS (
+  SELECT
+    tenant_id,
+    COUNT(*)                                      AS active_court_count
+  FROM staging.stg_playtomic_resources
+  WHERE is_active = TRUE
+  GROUP BY tenant_id
+)
+SELECT
+  v.tenant_id,
+  v.country_code,
+  v.city,
+  cc.active_court_count,
+  ROUND(wh.hours_open_per_week, 1)                AS hours_open_per_week,
+  ROUND(wh.avg_hours_open_per_day, 1)             AS avg_hours_open_per_day,
+  wh.days_open_per_week,
+  -- Total bookable court-hours per day (capacity denominator for occupancy)
+  ROUND(cc.active_court_count * wh.avg_hours_open_per_day, 1)  AS capacity_court_hours_per_day,
+  -- Total bookable court-hours per week
+  ROUND(cc.active_court_count * wh.hours_open_per_week, 1)     AS capacity_court_hours_per_week
+FROM staging.stg_playtomic_venues v
+JOIN court_counts cc ON v.tenant_id = cc.tenant_id
+JOIN weekly_hours wh ON v.tenant_id = wh.tenant_id