fix: Correct mv_state_metrics to use brand_name_raw

- Changed unique_brands from COUNT(brand_id) to COUNT(brand_name_raw)
- brand_id is often NULL, brand_name_raw has actual data
- AZ now correctly shows 462 brands (was 144)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/migrations/093_fix_mv_state_metrics.sql

@@ -0,0 +1,43 @@
+-- Migration: 093_fix_mv_state_metrics.sql
+-- Purpose: Fix mv_state_metrics to use brand_name_raw and show correct store counts
+-- Issues fixed:
+-- 1. unique_brands used brand_id (often NULL), now uses brand_name_raw
+-- 2. Added out_of_stock_products column
+-- 3. dispensary_count now correctly named
+
+-- Drop and recreate the materialized view with correct definition
+DROP MATERIALIZED VIEW IF EXISTS mv_state_metrics;
+
+CREATE MATERIALIZED VIEW mv_state_metrics AS
+SELECT
+  d.state,
+  s.name AS state_name,
+  COUNT(DISTINCT d.id) AS dispensary_count,
+  COUNT(DISTINCT CASE WHEN d.menu_type = 'dutchie' THEN d.id END) AS dutchie_stores,
+  COUNT(DISTINCT CASE WHEN d.crawl_enabled = true THEN d.id END) AS active_stores,
+  COUNT(sp.id) AS total_products,
+  COUNT(CASE WHEN COALESCE(sp.is_in_stock, true) THEN sp.id END) AS in_stock_products,
+  COUNT(CASE WHEN sp.is_in_stock = false THEN sp.id END) AS out_of_stock_products,
+  COUNT(CASE WHEN sp.is_on_special THEN sp.id END) AS on_special_products,
+  COUNT(DISTINCT sp.brand_name_raw) FILTER (WHERE sp.brand_name_raw IS NOT NULL AND sp.brand_name_raw != '') AS unique_brands,
+  COUNT(DISTINCT sp.category_raw) FILTER (WHERE sp.category_raw IS NOT NULL) AS unique_categories,
+  ROUND(AVG(sp.price_rec) FILTER (WHERE sp.price_rec > 0)::NUMERIC, 2) AS avg_price_rec,
+  MIN(sp.price_rec) FILTER (WHERE sp.price_rec > 0) AS min_price_rec,
+  MAX(sp.price_rec) FILTER (WHERE sp.price_rec > 0) AS max_price_rec,
+  NOW() AS refreshed_at
+FROM dispensaries d
+LEFT JOIN states s ON d.state = s.code
+LEFT JOIN store_products sp ON d.id = sp.dispensary_id
+WHERE d.state IS NOT NULL
+GROUP BY d.state, s.name;
+
+-- Create unique index for CONCURRENTLY refresh support
+CREATE UNIQUE INDEX idx_mv_state_metrics_state ON mv_state_metrics(state);
+
+-- Update refresh function
+CREATE OR REPLACE FUNCTION refresh_state_metrics()
+RETURNS void AS $$
+BEGIN
+  REFRESH MATERIALIZED VIEW CONCURRENTLY mv_state_metrics;
+END;
+$$ LANGUAGE plpgsql;