🎨 Palette: Add tooltips to icon-only chat buttons

[thirdeyenation]

💡 What: Added native title attributes to the More Actions (+), Expand, and Microphone buttons in the chat input bar.
🎯 Why: These buttons previously only had aria-label attributes, which are invisible to sighted users relying on a mouse. Adding native HTML tooltips makes the interface significantly more intuitive, as users can now discover the function of these buttons by hovering over them before clicking.
♿ Accessibility: Improves accessibility for non-screen-reader users who rely on visual tooltips to understand icon-only interactive elements.

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PR created automatically by Jules for task 8963983798962157296 started by @thirdeyenation

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