Feature: Support Code 39 symbology alongside existing QR and CODE128
- Added CODE39 option to code type dropdown (front and back sides)
- Updated renderOne() to handle code39 type with format parameter
- Code 39 shares CSS styling with CODE128 (linear barcode layout)
- Updated error message to be format-agnostic
Use case: Legacy systems and equipment that require Code 39 format
for compatibility (common in manufacturing and inventory systems)
Technical notes:
- JsBarcode library already supports CODE39 format
- Passed format parameter to barcodeSvgDataUri() function
- Both CODE128 and CODE39 use .type-barcode CSS class
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
