Migrate the entire admin section from the dark guild-* Tailwind theme
to the zine design system (dashed borders, CSS custom properties,
Brygada 1918 + Commit Mono, cream/dark mode palette).
- Replace admin top-nav layout with sidebar matching default layout
- Reskin dashboard, members, events, series management pages
- Reskin events/create and series/create form pages
- Add dev-only test login endpoint (GET /api/dev/test-login)
- Redirect duplicate admin/dashboard.vue to /admin
- Update CLAUDE.md design system docs
Invite tokens now include a redirect claim so the verify endpoint
can distinguish them from regular login tokens. Only invite links
redirect to wiki.ghostguild.org; normal logins go to /members.
Invite emails now include both plain text and HTML versions. The
{loginLink} placeholder renders as a styled button in HTML email
clients. Other URLs in the template are auto-linked. The auth verify
endpoint redirects to wiki.ghostguild.org instead of /members.
