🎨 Palette: Improve screen reader accessibility for AssetCard buttons

[thebearwithabite]

💡 What: Added aria-label attributes to the "Remove" and "Copy Name & Description" icon-only buttons within the AssetCard component in AssetLibrary.tsx. Also added aria-hidden="true" to the inner SVG icons.
🎯 Why: Without text labels, screen readers announce these buttons generically (often just as "button"), providing no context for visually impaired users. This micro-UX change ensures the buttons' actions are clearly communicated.
♿ Accessibility: Improved screen reader compatibility by explicitly defining button purposes and hiding decorative child SVGs from the accessibility tree.

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PR created automatically by Jules for task 13999562692650723145 started by @thebearwithabite

[google-labs-jules]

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