Move sales seasonality table to config schema and finish up standardizing scripts

inventory-server/db/config-schema.sql

@@ -88,6 +88,16 @@ CREATE TABLE IF NOT EXISTS turnover_config (
     UNIQUE KEY unique_category_vendor (category_id, vendor)
 );
 
+-- Create table for sales seasonality factors
+CREATE TABLE IF NOT EXISTS sales_seasonality (
+    month INT NOT NULL,
+    seasonality_factor DECIMAL(5,3) DEFAULT 0,
+    last_updated TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    PRIMARY KEY (month),
+    CHECK (month BETWEEN 1 AND 12),
+    CHECK (seasonality_factor BETWEEN -1.0 AND 1.0)
+);
+
 -- Insert default global thresholds if not exists
 INSERT INTO stock_thresholds (id, category_id, vendor, critical_days, reorder_days, overstock_days)
 VALUES (1, NULL, NULL, 7, 14, 90)
@@ -129,6 +139,13 @@ ON DUPLICATE KEY UPDATE
     calculation_period_days = VALUES(calculation_period_days),
     target_rate = VALUES(target_rate);
 
+-- Insert default seasonality factors (neutral)
+INSERT INTO sales_seasonality (month, seasonality_factor)
+VALUES 
+    (1, 0), (2, 0), (3, 0), (4, 0), (5, 0), (6, 0),
+    (7, 0), (8, 0), (9, 0), (10, 0), (11, 0), (12, 0)
+ON DUPLICATE KEY UPDATE last_updated = CURRENT_TIMESTAMP;
+
 -- View to show thresholds with category names
 CREATE OR REPLACE VIEW stock_thresholds_view AS
 SELECT