NexField Tech

- Added customer signature capture directly inside invoice details. - Customers can review Payment Terms, Terms & Conditions, and Warranty before signing. - Signature is saved to the invoice and synced with the web invoice view. - Improved signature pad touch handling so drawing does not scroll the screen. - Payment collection is locked until signature is completed, with an option to skip signature and collect payment if needed. - Improved light/dark theme switching, contrast, and readability. - Fixed visual issues in invoice buttons, client cards, order statuses, call player controls, and related UI elements.