Enhance Footer Social Media Icon Usability & Accessibility

### Problem
The website footer displays social media links as icons only (e.g., GitHub, Mastodon, etc.), but these have several usability and accessibility challenges:
- Icon-only links rely on user familiarity; users may not recognize all icons
- No label appears on hover, so destinations are not clearly communicated for sighted users
- Accessibility is limited for screen reader and keyboard users (insufficient labeling, ambiguous links)

### Proposed Enhancement
- Ensure each social icon link is a proper `` so that browsers show the destination URL on hover
- Add a hover label (tooltip or `title` attribute) indicating the platform name
- Add appropriate `aria-label` attributes to each link for accessibility
- Keep styling minimal and consistent with the current design

Start by locating the website footer markup and its existing social-media links, then inspect the rendered footer and current styles. Update only the footer links so each has a destination, platform-specific hover text, and an accessible label while preserving the existing appearance. Done means the links are clear on hover and usable with screen readers and keyboards without a major layout change.

Written by the indexing model from the issue text.