Nishat Linen Payroll v1.6.0

- Removed the payslip Style 1 / Style 2 / Style 3 selector.
- Fixed the former Style 3 layout as the single standard receipt design for single and batch printing.
- Added Settings > Print receipt image.
- Supports PNG, JPG, and WEBP up to 2 MB with image validation.
- Added current image preview, replace, remove, and Active in receipt controls.
- Uploaded receipt artwork is constrained to 58mm wide and 16mm high so the 80mm payslip remains compact.
- Removed the obsolete global payroll adjustment endpoint.
- Existing databases are upgraded automatically; no manual SQL import is required.

- Increased receipt header artwork area so uploaded print images display in a wider cover-photo style banner near the full receipt width.
- Root fix for print receipt image uploads: empty white/transparent margins are automatically trimmed so artwork no longer appears tiny in the middle of the receipt.
