Squashed 'common/' content from commit 28b2939

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git-subtree-split: 28b2939037b5932ca5d5a6c734b292c012ac675f

scripts/stats/shrinkflation_count.sql

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+-- =============================================================================
+-- Stat 1: Products that shrank in the past 12 months
+-- Validates: "847 products that shrank in the past 12 months" (launch announcement)
+--
+-- Run against production Postgres once infrastructure is available.
+-- Results will drift as the 12-month window slides forward from execution date.
+-- =============================================================================
+
+-- Primary count: distinct products with ≥1 shrinkflation event in the past year
+SELECT
+    COUNT(DISTINCT se.normalized_product_id) AS shrinkflation_product_count
+FROM shrinkflation_events se
+WHERE se.detected_date >= CURRENT_DATE - INTERVAL '12 months';
+
+
+-- Breakdown by product category (for deeper reporting)
+SELECT
+    COALESCE(np.category, 'unknown')       AS category,
+    COUNT(DISTINCT se.normalized_product_id) AS products_with_shrinkflation
+FROM shrinkflation_events se
+JOIN normalized_products np ON np.id = se.normalized_product_id
+WHERE se.detected_date >= CURRENT_DATE - INTERVAL '12 months'
+GROUP BY np.category
+ORDER BY products_with_shrinkflation DESC;
+
+
+-- Breakdown by confidence band (high/medium/low events)
+-- Confidence >= 0.80 = "clear" shrinkflation signal
+SELECT
+    CASE
+        WHEN se.confidence >= 0.80 THEN 'high (>=0.80)'
+        WHEN se.confidence >= 0.50 THEN 'medium (0.50-0.79)'
+        ELSE 'low (<0.50)'
+    END                                      AS confidence_band,
+    COUNT(DISTINCT se.normalized_product_id) AS products
+FROM shrinkflation_events se
+WHERE se.detected_date >= CURRENT_DATE - INTERVAL '12 months'
+GROUP BY confidence_band
+ORDER BY MIN(se.confidence) DESC;