Add new filter options and metrics to product filters and pages; enhance SQL schema for financial calculations

inventory-server/db/metrics-schema.sql

@@ -11,15 +11,17 @@ CREATE TABLE temp_sales_metrics (
     avg_margin_percent DECIMAL(10,3),
     first_sale_date DATE,
     last_sale_date DATE,
+    stddev_daily_sales DECIMAL(10,3),
     PRIMARY KEY (pid)
 );
 
 CREATE TABLE temp_purchase_metrics (
     pid BIGINT NOT NULL,
-    avg_lead_time_days INTEGER,
+    avg_lead_time_days DECIMAL(10,2),
     last_purchase_date DATE,
     first_received_date DATE,
     last_received_date DATE,
+    stddev_lead_time_days DECIMAL(10,2),
     PRIMARY KEY (pid)
 );
 
@@ -50,7 +52,7 @@ CREATE TABLE product_metrics (
     gross_profit DECIMAL(10,3),
     gmroi DECIMAL(10,3),
     -- Purchase metrics
-    avg_lead_time_days INTEGER,
+    avg_lead_time_days DECIMAL(10,2),
     last_purchase_date DATE,
     first_received_date DATE,
     last_received_date DATE,