Installed skills for the SvelteKit/Tailwind/Vite stack under
web-player/.agents/skills (source of truth) with web-player/.claude/skills
symlinked to it for tool compatibility, plus skills-lock.json tracking
each skill's registry source and content hash.
Updates the compose build context, the Dockerfile header, the package
name and the docs. The compose service and container keep the name
frontend/musify-frontend, since nginx routes to http://frontend:3000.
The source files also carry the first prettier pass, so the rename and
the reformat land together for them.