fix: point Tyler Gibbs testimonial at his current avatar

[chakravartiavinit]

Issue

The Tyler Gibbs testimonial on the landing page renders a broken-image icon instead of an avatar.

TestimonialCard hotlinks the author's pbs.twimg.com profile image. Twitter mints a new profile-image path whenever a user changes their picture and lets the old path 404 — Tyler changed his, so the stored URL

https://pbs.twimg.com/profile_images/2068918593962536960/gmAsn6Nj_normal.jpg

now returns 404 in every size variant (_normal, _bigger, _200x200, bare). The card renders <img> with no error fallback, so the dead URL shows as the browser's broken-image glyph next to the name and handle.

Fix

Point the entry at his current avatar (2077596476687998978/WvlUT0v1). Verified 200 both as stored (_normal) and as rendered — TestimonialCard rewrites _normal → _bigger.

Checks

• Swept every avatar URL in testimonials-data.ts on main in its rendered form; Tyler's is the only dead one.
• bun run typecheck and bun run lint clean (lint's 3 noImgElement warnings in attachment-upload.tsx are pre-existing and untouched).

Not done

No onError fallback in TestimonialCard — it would make the card a client component for a failure mode that has hit once. Worth adding if a second avatar rots. Migrating avatars to unavatar.io was considered and dropped: it 403'd on one handle during testing and adds ~1s per image.