🎨 Palette: Add ARIA labels to icon-only buttons in IdentityManager

[thebearwithabite]

💡 What: Added aria-label, title, and standard focus-visible ring styling to the Edit, Delete, and Close dialog buttons in the IdentityManager settings component. The inner SVG icons were also marked with aria-hidden="true".

🎯 Why: These buttons contained only icons without visible text, making them completely inaccessible to screen reader users and confusing for keyboard navigators since they lacked focus rings or hover tooltips.

♿ Accessibility:

• Sighted users now get a helpful native tooltip on hover.
• Screen readers will correctly announce "Edit [Name]", "Delete [Name]", or "Close dialog" instead of reading generic button roles or attempting to parse the SVG content.
• Keyboard users receive a clear visual focus indicator when tabbing through the identity list.

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PR created automatically by Jules for task 16880382698081319679 started by @thebearwithabite

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