🎨 Palette: Add focus states and ARIA labels to TabbedHelpModal close button

[aafre]

💡 What: Added type="button", an aria-label="Close help modal", and explicit focus-visible styles to the custom MdClose button inside the TabbedHelpModal. Also created a palette.md journal entry detailing this learning.

🎯 Why: Custom icon-only modal close buttons without explicit focus outlines fail accessibility standards because they do not provide clear visual feedback to keyboard users (even if they have hover states). Without an aria-label, screen readers may not accurately describe the action. Adding type="button" ensures it doesn't accidentally trigger forms.

♿ Accessibility:

• Added aria-label="Close help modal" for screen readers.
• Added focus:outline-none focus-visible:ring-2 focus-visible:ring-accent focus-visible:ring-offset-2 for keyboard navigators.
• Added type="button" to avoid unintended form behavior.

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PR created automatically by Jules for task 14399274600887456440 started by @aafre

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[gemini-code-assist]

Code Review

This pull request improves the accessibility of the close button in the TabbedHelpModal component by adding explicit focus styles, a button type, and an ARIA label, alongside documenting these guidelines in .jules/palette.md. Feedback was provided to add padding and a hover background to the close button to increase its touch target size and improve the visual layout of the focus ring.

[gemini-code-assist]

The close button currently lacks padding, resulting in a very small interactive target area (24x24 pixels) that is difficult to tap on mobile devices and violates touch target size accessibility guidelines. Additionally, without padding, the focus ring is drawn tightly against the edges of the icon, which looks cramped. Adding padding (e.g., 'p-1.5') and a subtle hover background (like 'hover:bg-gray-100') will improve both the touch target size and the visual appearance of the focus ring, aligning it with other close buttons in the codebase (such as the one in 'PreviewModal').

Suggested change

	className="text-gray-400 hover:text-gray-600 transition-colors focus:outline-none focus-visible:ring-2 focus-visible:ring-accent focus-visible:ring-offset-2 rounded-lg"
	className="p-1.5 text-gray-400 hover:text-gray-600 hover:bg-gray-100 transition-colors focus:outline-none focus-visible:ring-2 focus-visible:ring-accent focus-visible:ring-offset-2 rounded-lg"