🎨 Palette: Add ARIA labels to task action buttons

[thirdeyenation]

💡 What: Added aria-label attributes to the icon-only buttons for tasks in the sidebar.
🎯 Why: Improves accessibility for screen readers navigating the task list, providing context for the action buttons (View details, Clear chat, Delete task).
📸 Before/After: Visuals are unchanged. Added aria-label attribute to HTML tags.
♿ Accessibility: Improved keyboard accessibility and screen reader support for the task action buttons.

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PR created automatically by Jules for task 14337446919841480113 started by @thirdeyenation

[google-labs-jules]

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