feat: Playtomic pricing/occupancy pipeline + email i18n + audience restructure

Three workstreams:

1. Playtomic full data extraction & transform pipeline:
   - Expand venue bounding boxes from 4 to 23 regions (global coverage)
   - New staging models for court resources, opening hours, and slot-level
     availability with real prices from the Playtomic API
   - Foundation fact tables for venue capacity and daily occupancy/revenue
   - City-level pricing benchmarks replacing hardcoded country estimates
   - Planner defaults now use 3-tier cascade: city data → country → fallback

2. Transactional email i18n:
   - _t() helper in worker.py with ~70 translation keys (EN + DE)
   - All 8 email handlers translated, lang passed in task payloads

3. Resend audiences restructured to 3 named audiences (free plan limit)

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

transform/sqlmesh_padelnomics/models/foundation/fct_daily_availability.sql

@@ -0,0 +1,90 @@
+-- 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.
+--
+-- Occupancy = 1 - (available_court_hours / capacity_court_hours_per_day)
+-- Revenue estimate = booked_court_hours × avg_price_of_available_slots
+--
+-- Peak hours defined as 17:00–21:00 (captures main evening rush across markets).
+
+MODEL (
+  name foundation.fct_daily_availability,
+  kind FULL,
+  cron '@daily',
+  grain (snapshot_date, tenant_id)
+);
+
+WITH slot_agg AS (
+  SELECT
+    a.snapshot_date,
+    a.tenant_id,
+    -- Slot counts: each row is one 60-min available slot on one court
+    COUNT(*)                                              AS available_slot_count,
+    COUNT(DISTINCT a.resource_id)                         AS courts_with_availability,
+    -- Available (unbooked) court-hours: slots are on 30-min increments for 60-min bookings
+    -- Each available start_time represents a 60-min bookable window
+    ROUND(COUNT(*) * 1.0, 2)                              AS available_court_hours,
+    -- Pricing stats (60-min slots only)
+    ROUND(MEDIAN(a.price_amount), 2)                      AS median_price,
+    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,
+    -- 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,
+    MAX(a.price_currency)                                 AS price_currency,
+    MAX(a.captured_at_utc)                                AS captured_at_utc
+  FROM staging.stg_playtomic_availability a
+  WHERE a.price_amount IS NOT NULL
+    AND a.price_amount > 0
+  GROUP BY a.snapshot_date, a.tenant_id
+)
+SELECT
+  sa.snapshot_date,
+  sa.tenant_id,
+  cap.country_code,
+  cap.city,
+  cap.active_court_count,
+  cap.capacity_court_hours_per_day,
+  sa.available_slot_count,
+  sa.courts_with_availability,
+  sa.available_court_hours,
+  -- Occupancy: (capacity - available) / capacity
+  CASE
+    WHEN cap.capacity_court_hours_per_day > 0
+    THEN ROUND(
+      1.0 - (sa.available_court_hours / cap.capacity_court_hours_per_day),
+      4
+    )
+    ELSE NULL
+  END                                                     AS occupancy_rate,
+  -- Estimated booked court-hours
+  ROUND(
+    GREATEST(cap.capacity_court_hours_per_day - sa.available_court_hours, 0),
+    2
+  )                                                       AS booked_court_hours,
+  -- Estimated daily revenue: booked hours × avg price
+  ROUND(
+    GREATEST(cap.capacity_court_hours_per_day - sa.available_court_hours, 0)
+    * sa.avg_price,
+    2
+  )                                                       AS estimated_revenue_eur,
+  -- Pricing
+  sa.median_price,
+  sa.avg_price,
+  sa.min_price,
+  sa.max_price,
+  sa.median_price_peak,
+  sa.median_price_offpeak,
+  sa.price_currency,
+  sa.captured_at_utc
+FROM slot_agg sa
+JOIN foundation.fct_venue_capacity cap ON sa.tenant_id = cap.tenant_id