Replace emoji operator icons (➕➖✖️➗) with ASCII characters
(+ − × ÷) that properly inherit font colors in dark mode.
Changes:
- Update SETTING_ICONS to use ASCII: +, −, ×, ÷, ±
- Update TabNavigation operator icon function to match
- Change styling check from isPlusMinus to isOperatorSymbol
- All operator symbols now display correctly in light and dark modes
Fixes issue where emoji operators stayed dark in dark mode because
they don't inherit text color properties.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
3bd5c00d21