My live store runs on osCommerce v2.2 and currently sits on a PHP 5.6 server. I need every line of that codebase—core files and roughly twenty hand-rolled tweaks—to execute cleanly on PHP 8.4 while leaving the storefront’s look, feel, and workflow unchanged. Upgrading osCommerce itself is off the table; the task is a careful refactor of the existing code so it loads without deprecated warnings, removed-function errors, or compatibility shims. Key points you should know: • Custom modifications are present, but there is zero written documentation for them, so part of the assignment is to trace and preserve this bespoke logic. • No third-party modules to worry about—only my original edits. • I will supply full source, database dump, and a staging cPanel with PHP 8.4 enabled for your testing. Deliverables I expect: 1. Fully patched codebase running error-free on PHP 8.4 in the staging environment, then migrated to production. 2. A concise change log noting every file touched, the issue addressed, and the solution applied. 3. Smoke-test checklist (checkout flow, admin orders, basic reports) showing all critical paths verified. Acceptance criteria: the storefront and admin must operate identically to the current live site under load testing, with no fatal errors and no deprecated notices displayed in error_reporting = E_ALL. If anything is unclear, let me know and I’ll provide direct access or screenshots to speed your audit.