🎨 Palette: Improve navigation accessibility with ARIA labels

[vireapp]

💡 What: Added aria-label to MobileNav links and DashboardLayout header buttons (Settings, Logout).
🎯 Why: Screen reader users on mobile and desktop could not identify these icon-only buttons/links.
♿ Accessibility: Added descriptive aria-label attributes to 4 navigation links and 2 action buttons.
Reference: MobileNav issue.

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PR created automatically by Jules for task 10521780160048038479 started by @vireapp

[google-labs-jules]

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