QR code scanner does not recognize inverted QR codes (white on black)

[AxelHamburch]

Description:

The Phoenix Wallet QR code scanner fails to recognize inverted QR codes where pixels are displayed as white on black background instead of the standard black on white.

Expected Behavior:
Scanner should recognize both standard and inverted QR codes.

Current Behavior:

• Standard QR codes (black on white): ✅ Recognized
• Inverted QR codes (white on black): ❌ Not recognized

Steps to Reproduce:

1. Generate a Lightning invoice or LNURL QR code
2. Display it with inverted colors (white on black)
3. Try to scan with Phoenix Wallet
4. Scanner fails to detect the code

Use Case:
Some Lightning systems display inverted QR codes for better visibility on OLED screens or dark mode interfaces. This limits interoperability with these systems.

Additional Context:

• Wallet of Satoshi, Zeus, and Alby Go correctly recognize inverted QR codes
• ISO/IEC 18004 QR code specification allows inverted patterns
• Affects both Lightning invoices and LNURL codes

Example: