🎨 Palette: Expand clickable area and improve accessibility for category rows

[acebytes]

💡 What
Wrapped the CategoryRow's HStack inside a Button with .contentShape(Rectangle()) to make the entire row clickable.

🎯 Why
Previously, only the small circular checkbox icon was clickable. This was a poor UX pattern that required precise mouse/trackpad positioning. By making the whole row clickable, users can easily select and deselect cache categories.

📸 Before/After
Before: Click target limited to a ~20x20px circle icon.
After: Click target expands to the full width and height of the row.

♿ Accessibility
Added .accessibilityElement(children: .combine) and .accessibilityAddTraits(result.isSelected ? .isSelected : []). This unifies the row's child text elements (name, description, size) into a single cohesive VoiceOver announcement and properly communicates the selected state.

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PR created automatically by Jules for task 4683801814068669321 started by @acebytes

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