Prestige Barber Club v4.40.9 Build Test

PASS - Full PHP syntax audit: 194 PHP files, 0 errors.
PASS - All upgrade_v*.php page_header calls use $pdo as first argument.
PASS - Pra-Member expired calculation uses historical join_date + historical validity.
PASS - Expired discount is recalculated server-side from Branding settings and selected package price.
PASS - Discount supports fixed Rupiah and percent with price cap.
PASS - Pra-Member validity accepts official values 6/12/18/24/36/48/60 months.
PASS - Membership sale snapshots validity_months/start_date/end_date.
PASS - Activation uses snapshot dates, preserving original Pra-Member join_date.
PASS - Existing v4.40.8 Cash/QRIS no-proof behavior retained.
PASS - No CREATE DATABASE / USE introduced.

Note: production DB/browser integration cannot be executed from this build environment. Run upgrade_v4_40_9.php after deployment.
