Enhance Greyscale Mode Accessibility for UI Buttons

The app currently uses red color changes to indicate if buttons like "Web Search" or "Reasoning" are active or disabled. This visual cue is ineffective in greyscale mode, making it hard to determine button states for users relying on this display setting.

To improve accessibility, additional visual indicators—such as borders, textures, text labels ("Enabled"/"Disabled"), or brightness changes—should be added to clearly show button status in greyscale mode. This will ensure a more inclusive and user-friendly experience for those with visual impairments.