Perfex Custom Themes & Client Area

Use whenever the user is building or debugging a Perfex CRM custom client-area theme — files under `assets/themes/<theme>/` and `application/views/themes/<theme>/`, asset injection via `app_customers_head`/`app_customers_footer`/`app_admin_head`/`app_admin_footer` hooks, overriding core views, dark mode with `[data-theme="dark"]` plus anti-FOUC `<head>` scripts, RTL/Arabic support, or the jQuery Validate bug where a submit button's `name` is stripped from POST (breaks "Pay Now" / "Save Draft" detection). Also trigger when the user says "my theme CSS is cached after deploy", "Pay Now button loses its value", "jQuery Validate ate my button name", "client area dark mode", "t…