Sonnet model shows AUTO permission mode but fails with error

Reproduction

1. Desktop app → select Sonnet model
2. Permission mode dropdown shows AUTO as available option
3. Click AUTO → error in upper right: "Permission mode couldn't be changed. You can try again."

Expected

• AUTO mode either works (like Opus) OR is disabled (like Haiku)
• Consistent behavior across all models

Actual

• Sonnet shows AUTO available but throws error when selected
• Forces manual mode switch every session

Environment

• Claude Code Desktop App
• Sonnet model only (Opus: AUTO works; Haiku: AUTO correctly disabled)