feat(ui): 🎨 Palette: Improve dashboard empty state and button accessibility

[myarichuk]

🎨 Palette: Improve dashboard empty state and button accessibility

• 💡 What:
  • Added explicit type="button" attributes to interactive <button> elements in Home.razor.
  • Upgraded the "Recent Archives" empty state to use a modern, structured layout with an icon and clear heading.
• 🎯 Why:
  • Prevents unexpected browser behaviors (accidental form submissions) caused by missing type="button".
  • Improves visual consistency by bringing the table's empty state in line with the rest of the application's empty states.
• ♿ Accessibility:
  • Better semantic HTML compliance.

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PR created automatically by Jules for task 12127318280319970829 started by @myarichuk

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