bug: favicon is hard to see in dark mode

Inizia individuando il /favicon.ico statico citato nel report e verifica come il browser gestisce prefers-color-scheme per i favicon assets. Il lavoro è completato quando il favicon rimane distinguibile nei temi chiaro e scuro del browser in tutti i browser supportati.

Describe the bug
The favicon does not adapt to the browser's theme preference, appearing dark/low-contrast against dark browser tabs in dark mode. This affects user experience across all markets (e.g., Ethereum V3, Polygon V3, Arbitrum V3) as the favicon becomes difficult to distinguish in dark browser themes.

To Reproduce
Steps to reproduce the behavior:

1. Go to 'https://app.aave.com' (or any Aave market)
2. Switch your system to dark mode (macOS: System Preferences → General → Appearance → Dark)
3. Observe the browser tab containing the Aave app
4. See the favicon appears dark/low-contrast against the dark browser tab background

Expected behavior
The favicon should automatically adapt to the browser's theme preference:

• Light mode: Display the current favicon design with good contrast against light browser tabs
• Dark mode: Display a lighter/higher-contrast version of the favicon that is clearly visible against dark browser tabs

Screenshots

Aave favicon in light and dark mode

Compared with lens favicon in light and dark mode

Appearance in MetaMask extension

Desktop (please complete the following information):

• OS: macOS 14.5.0 (affects all operating systems with dark mode support)
• Browser: Chrome 91+, Firefox 67+, Safari 12.1+, Edge 79+
• Version: All recent versions that support prefers-color-scheme

Smartphone (please complete the following information):

• Device: iPhone, Android devices
• OS: iOS 13+, Android 10+ (any OS with system dark mode)
• Browser: Safari (iOS), Chrome (Android), Firefox Mobile
• Version: All recent mobile browser versions

Additional context

Technical Details:

• Current favicon implementation uses a static /favicon.ico file that doesn't respond to theme changes
• Modern browsers support prefers-color-scheme media queries for automatic theme detection
• Many other DeFi applications (Uniswap, Compound, etc.) have implemented theme-aware favicons

Impact:

• UX Issue: Users in dark mode struggle to identify the Aave tab among multiple open tabs
• Brand Consistency: The favicon doesn't match the app's sophisticated theme-switching capabilities
• Accessibility: Poor contrast ratios in dark mode may affect users with visual impairments

Browser Support:

• Chrome 76+: Full SVG favicon support with media queries
• Firefox 67+: Full support
• Safari 12.1+: Full support
• Edge 79+: Full support
• Coverage: ~95% of users globally

Priority: Low (affects all users, impacts brand perception and accessibility)