# Receipt Layout & Preview v56

## Goal
Validate receipt/kitchen-ticket raster layout without requiring physical thermal hardware.

## Principle
The PNG preview is reconstructed from the same 1-bit raster buffer that is
encoded into ESC/POS `GS v 0`.

Therefore preview validation covers the actual:
- width
- wrapping
- Arabic/RTL shaping output
- spacing
- barcode placement
- monochrome threshold

It does not validate physical printer mechanics such as:
- thermal density
- feed calibration
- cutter
- firmware raster limits

## Paper profiles
- thermal_58: 384 px @ 203 DPI
- thermal_80: 576 px @ 203 DPI

## v56 structured operators
- text
- key_value
- item
- total
- divider
- spacer
- kitchen_item
- barcode_code128

## Barcode
Code 128-B is rendered directly into the bitmap so preview and thermal output
share identical bars.

## QR
QR is intentionally deferred until a standards-compliant matrix encoder with
error correction is integrated. No placeholder QR is allowed.
