'rebuilt missing sales and staff pages

backup-website/add_service_id_column.sql

@@ -0,0 +1,10 @@
+-- Add missing service_id column to gsp_billing_invoices table
+-- This column is required to track which service/game plan was purchased
+-- Table prefix is hardcoded to gsp_ for standalone billing module
+
+ALTER TABLE `gsp_billing_invoices` 
+ADD COLUMN `service_id` INT(11) NOT NULL AFTER `user_id`;
+
+-- Add index for better query performance
+ALTER TABLE `gsp_billing_invoices`
+ADD KEY `service_id` (`service_id`);