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/fct_daily_availability.sql

@@ -1,11 +1,9 @@
 -- Daily venue-level availability, pricing, occupancy, and revenue estimates.
--- Aggregates slot-level data from stg_playtomic_availability into per-venue
--- per-day statistics, then calculates occupancy by comparing available hours
--- against total capacity from fct_venue_capacity.
+-- Aggregates fct_availability_slot (event-grain fact) into per-venue per-day
+-- statistics, then calculates occupancy against capacity from dim_venue_capacity.
 --
--- Recheck-aware occupancy: for each (tenant, resource, slot_start_time),
--- prefer the latest snapshot (recheck > morning). A slot present in morning
--- but absent in the recheck = booked between snapshots → more accurate occupancy.
+-- Recheck-aware deduplication lives in fct_availability_slot — this model only
+-- reads the already-deduplicated best-snapshot slots.
 --
 -- Occupancy = 1 - (available_court_hours / capacity_court_hours_per_day)
 -- Revenue estimate = booked_court_hours × avg_price_of_available_slots
@@ -19,26 +17,7 @@ MODEL (
   grain (snapshot_date, tenant_id)
 );
 
--- Prefer the latest snapshot for each slot:
--- If a recheck exists for a (date, tenant, resource, start_time), use it.
--- Otherwise fall back to the morning snapshot.
-WITH ranked_slots AS (
-  SELECT
-    a.*,
-    ROW_NUMBER() OVER (
-      PARTITION BY a.snapshot_date, a.tenant_id, a.resource_id, a.slot_start_time
-      ORDER BY
-        CASE WHEN a.snapshot_type = 'recheck' THEN 1 ELSE 2 END,
-        a.captured_at_utc DESC
-    ) AS rn
-  FROM staging.stg_playtomic_availability a
-  WHERE a.price_amount IS NOT NULL
-    AND a.price_amount > 0
-),
-latest_slots AS (
-  SELECT * FROM ranked_slots WHERE rn = 1
-),
-slot_agg AS (
+WITH slot_agg AS (
   SELECT
     a.snapshot_date,
     a.tenant_id,
@@ -51,19 +30,13 @@ slot_agg AS (
     ROUND(AVG(a.price_amount), 2)                         AS avg_price,
     MIN(a.price_amount)                                   AS min_price,
     MAX(a.price_amount)                                   AS max_price,
-    -- Peak: 17:00–21:00
-    ROUND(MEDIAN(a.price_amount) FILTER (
-      WHERE a.slot_start_time::TIME >= '17:00:00'
-        AND a.slot_start_time::TIME < '21:00:00'
-    ), 2)                                                 AS median_price_peak,
+    -- Peak: 17:00–21:00 (is_peak flag computed once in fct_availability_slot)
+    ROUND(MEDIAN(a.price_amount) FILTER (WHERE a.is_peak), 2)       AS median_price_peak,
     -- Off-peak: everything outside 17:00–21:00
-    ROUND(MEDIAN(a.price_amount) FILTER (
-      WHERE a.slot_start_time::TIME < '17:00:00'
-         OR a.slot_start_time::TIME >= '21:00:00'
-    ), 2)                                                 AS median_price_offpeak,
+    ROUND(MEDIAN(a.price_amount) FILTER (WHERE NOT a.is_peak), 2)   AS median_price_offpeak,
     MAX(a.price_currency)                                 AS price_currency,
     MAX(a.captured_at_utc)                                AS captured_at_utc
-  FROM latest_slots a
+  FROM foundation.fct_availability_slot a
   GROUP BY a.snapshot_date, a.tenant_id
 )
 SELECT
@@ -106,4 +79,4 @@ SELECT
   sa.price_currency,
   sa.captured_at_utc
 FROM slot_agg sa
-JOIN foundation.fct_venue_capacity cap ON sa.tenant_id = cap.tenant_id
+JOIN foundation.dim_venue_capacity cap ON sa.tenant_id = cap.tenant_id