Run once after adding {:linea_ui, ...} to mix.exs, and again after each upgrade:
mix linea_ui.installIt writes the Claude Code skill (mix linea_ui.gen.skill), points AGENTS.md and
CLAUDE.md (those that exist) at it, and prints the lines to add to app.css, app.js
and the endpoint, and the lines for the optional Hugeicons icon set. Running it twice changes nothing the
second time.