🎨 Palette: Add ARIA label to ViewControls icon buttons

[endlessblink]

💡 What: Added dynamic :aria-label attributes to the filter-toggle and done-toggle icon-only buttons in the ViewControls component.
🎯 Why: Icon-only buttons relying solely on the title attribute for accessibility are handled inconsistently by screen readers. Providing an explicit aria-label ensures all users are fully informed of the current active action the button performs.
♿ Accessibility: The ARIA labels are bound dynamically (hideDoneTasks ? 'Show completed tasks' : 'Hide completed tasks') so they match the toggle states exactly and convey their true purpose instead of static descriptions.

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PR created automatically by Jules for task 642836219335258796 started by @endlessblink

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