Move allauth + auth UI to legacy/

allauth/ (44 files) is a django-allauth React UI — a separate concern
from the Mizan protocol. Moved to legacy/ pending extraction into a
standalone mizan-django-allauth package.

Also moved to legacy/:
- client/AuthContext.tsx — generic auth state from /me endpoint
- client/RouterContext.tsx — framework-agnostic router adapter
- client/routing.tsx — UserRoute/StaffRoute/AnonymousRoute guards
- client/nextjs.tsx — Next.js router adapter for auth

These are auth UI infrastructure, not Mizan protocol. The Mizan core
only needs JWT for auth header selection (jwt/ stays — MizanProvider
depends on useJWT() to decide between Bearer and session auth).

Cleaned up re-exports in client/react.ts and vitest aliases.

33 React tests pass.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

legacy/allauth/components/settings/index.ts

@@ -0,0 +1,20 @@
+// Main settings component
+export { AuthSettings } from './AuthSettings'
+
+// Individual sections (for custom layouts)
+export { ProfileSection } from './ProfileSection'
+export { EmailsSection } from './EmailsSection'
+export { PasswordSection } from './PasswordSection'
+export { PasskeysSection } from './PasskeysSection'
+export { ConnectionsSection } from './ConnectionsSection'
+export { MFASection } from './MFASection'
+export { SessionsSection } from './SessionsSection'
+
+// Building blocks (for custom components)
+export {
+    SettingsSection,
+    SettingsItem,
+    SettingsList,
+    Badge,
+    Button,
+} from './SettingsComponents'