Fix: add hover and focus-visible styles to contact section links

[claude]

Fixes #52

What changed

Added :hover and :focus-visible states to .contact-item a in demo/index.html:

.contact-item a:hover,
.contact-item a:focus-visible {
    text-decoration: underline;
    outline: 2px solid #61afef;
    outline-offset: 2px;
}

Why

The three contact links (@nesalot, jmerrell, say hello) had no visual feedback on hover and no visible focus indicator for keyboard users. This violated WCAG 2.4.7 Focus Visible (Level AA). Every other interactive link group on the page already had a hover state; this brings contact links in line.

How to verify

• Mouse: hover over any contact link — it should show an underline and blue outline.
• Keyboard: Tab to any contact link — the same outline should appear via :focus-visible.