Arc 0.8.0

Arc 0.8.0

• Add the application-owned, immutable UiRegistry with typed host, template, navigation, shell
  action, page, and form contracts.
• Split browser administration into the new arc-auth-admin crate; arc-auth-session is now a
  headless cookie/session protocol and middleware package with no Tera dependency.
• Add host-rendered sign-in, profile/password, and resource-grade Users administration, including
  filtering, pagination, detail/create/edit pages, roles, activation, and final-admin safeguards.
• Render generated resources and authentication capabilities through the same host shell, with a
  visible CSRF-protected sign-out action and reusable accessible field primitives.
• Stop capability navigation from modifying application layouts and add auth-admin to the
  auth-db-session installation bundle.

This is a breaking pre-1.0 release. Existing UI applications should preserve customized layouts
and migrate their builder wiring to register a UiHost before installing browser UI capabilities.