Six of the ten profiles rendered the same robot, because the map in
WelcomeScreen only knew four ids. The map moves to utils/profileIcons.js,
covers all ten — including the close pairs (`coder`/`developer`, the two
3D profiles) — and falls back to a hashed glyph from a pool rather than
one robot, so custom profiles differ from each other and stay stable
across renders. Covered by five unit tests.

Cards were ragged because each row took the height of its own content:
`grid-auto-rows: 1fr` makes every row as tall as the tallest card. A
fixed pixel height was the obvious alternative and is worse — "Server
Administrator" wraps on a phone. A three-line clamp on the desktop
description keeps one wordy profile from inflating every row.