Fix schema: add missing tables and correct forecast_snapshots structure

- Add booking_com_hotels and booking_com_rates (competitor rate scraper tables)
- Fix forecast_snapshots: was using old pivoted schema (snapshot_date,
  prophet_value etc.); code expects normalised rows (perception_date, model,
  forecast_value, actual_value). Add DO block migration to drop+recreate if
  old schema is detected.

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

backend/schema.sql

@@ -273,6 +273,45 @@ CREATE TABLE IF NOT EXISTS booking_scrape_log (
 
 CREATE INDEX IF NOT EXISTS idx_booking_scrape_log_started ON booking_scrape_log(started_at DESC);
 
+-- ============================================
+-- COMPETITOR RATE SCRAPER (booking.com hotels and rates)
+-- ============================================
+
+CREATE TABLE IF NOT EXISTS booking_com_hotels (
+    id SERIAL PRIMARY KEY,
+    booking_com_id VARCHAR(50) UNIQUE,
+    name VARCHAR(255) NOT NULL,
+    booking_com_url TEXT,
+    star_rating DECIMAL(2,1),
+    review_score DECIMAL(3,1),
+    review_count INTEGER DEFAULT 0,
+    tier VARCHAR(20) DEFAULT 'market',
+    display_order INTEGER DEFAULT 999,
+    notes TEXT,
+    is_active BOOLEAN DEFAULT TRUE,
+    first_seen_at TIMESTAMPTZ DEFAULT NOW(),
+    last_seen_at TIMESTAMPTZ DEFAULT NOW()
+);
+
+CREATE TABLE IF NOT EXISTS booking_com_rates (
+    id SERIAL PRIMARY KEY,
+    hotel_id INTEGER NOT NULL REFERENCES booking_com_hotels(id) ON DELETE CASCADE,
+    rate_date DATE NOT NULL,
+    availability_status VARCHAR(30),
+    rate_gross DECIMAL(10,2),
+    currency VARCHAR(10) DEFAULT 'GBP',
+    room_type VARCHAR(100),
+    breakfast_included BOOLEAN DEFAULT FALSE,
+    free_cancellation BOOLEAN DEFAULT FALSE,
+    no_prepayment BOOLEAN DEFAULT FALSE,
+    rooms_left INTEGER,
+    scrape_batch_id UUID REFERENCES booking_scrape_log(batch_id),
+    scraped_at TIMESTAMPTZ DEFAULT NOW()
+);
+
+CREATE INDEX IF NOT EXISTS idx_booking_com_rates_hotel_date ON booking_com_rates(hotel_id, rate_date);
+CREATE INDEX IF NOT EXISTS idx_booking_com_rates_date ON booking_com_rates(rate_date);
+
 -- ============================================
 -- SYNC LOGGING
 -- ============================================
@@ -663,22 +702,45 @@ CREATE TABLE IF NOT EXISTS daily_budgets (
 
 CREATE INDEX IF NOT EXISTS idx_daily_budgets_date ON daily_budgets(date, budget_type);
 
--- Forecast snapshots (for tracking how forecasts evolve over time)
+-- Forecast snapshots (one row per perception_date+target_date+model+metric)
 CREATE TABLE IF NOT EXISTS forecast_snapshots (
     id SERIAL PRIMARY KEY,
-    snapshot_date DATE NOT NULL,
+    perception_date DATE NOT NULL,
     target_date DATE NOT NULL,
+    model VARCHAR(50) NOT NULL,
     metric_code VARCHAR(50) NOT NULL,
-    days_out INTEGER NOT NULL,
+    days_out INTEGER,
-    prophet_value DECIMAL(12,2),
+    forecast_value DECIMAL(12,2),
-    xgboost_value DECIMAL(12,2),
+    actual_value DECIMAL(12,2),
-    pickup_value DECIMAL(12,2),
-    catboost_value DECIMAL(12,2),
     created_at TIMESTAMP DEFAULT NOW(),
-    UNIQUE(snapshot_date, target_date, metric_code)
+    UNIQUE(perception_date, target_date, model, metric_code)
 );
 
+-- Migration: drop old pivoted-column schema and recreate if snapshot_date column exists
+DO $$
+BEGIN
+    IF EXISTS (
+        SELECT 1 FROM information_schema.columns
+        WHERE table_name = 'forecast_snapshots' AND column_name = 'snapshot_date'
+    ) THEN
+        DROP TABLE forecast_snapshots;
+        CREATE TABLE forecast_snapshots (
+            id SERIAL PRIMARY KEY,
+            perception_date DATE NOT NULL,
+            target_date DATE NOT NULL,
+            model VARCHAR(50) NOT NULL,
+            metric_code VARCHAR(50) NOT NULL,
+            days_out INTEGER,
+            forecast_value DECIMAL(12,2),
+            actual_value DECIMAL(12,2),
+            created_at TIMESTAMP DEFAULT NOW(),
+            UNIQUE(perception_date, target_date, model, metric_code)
+        );
+    END IF;
+END $$;
+
 CREATE INDEX IF NOT EXISTS idx_forecast_snapshots_target ON forecast_snapshots(target_date, metric_code);
+CREATE INDEX IF NOT EXISTS idx_forecast_snapshots_perception ON forecast_snapshots(perception_date, model, metric_code);
 
 -- ============================================
 -- USER ROLES (migration for existing users table)