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/AuthCard.tsx

@@ -0,0 +1,85 @@
+'use client'
+
+import { ReactNode } from 'react'
+import { useRouter } from '../contexts/RouterContext'
+import { useStyles } from '../contexts/StylesContext'
+
+interface FooterLink {
+    label: string
+    href?: string
+    onClick?: () => void
+}
+
+interface AuthCardProps {
+    title: string
+    subtitle?: string
+    children?: ReactNode
+    footerLinks?: FooterLink[]
+    error?: string
+    success?: string
+    loading?: boolean
+    loadingText?: string
+}
+
+export function AuthCard({
+    title,
+    subtitle,
+    children,
+    footerLinks,
+    error,
+    success,
+    loading,
+    loadingText = 'Loading...',
+}: AuthCardProps) {
+    const router = useRouter()
+    const styles = useStyles()
+
+    const handleLinkClick = (e: React.MouseEvent, href: string) => {
+        e.preventDefault()
+        router.push(href)
+    }
+
+    return (
+        <div className={styles.container}>
+            <div className={styles.card}>
+                {loading ? (
+                    <div className={styles.loading}>
+                        <div className={styles.spinner} />
+                        <p className={styles.subtitle}>{loadingText}</p>
+                    </div>
+                ) : (
+                    <>
+                        <h1 className={styles.title}>{title}</h1>
+                        {subtitle && <p className={styles.subtitle}>{subtitle}</p>}
+
+                        {error && <div className={styles.error}>{error}</div>}
+                        {success && <div className={styles.success}>{success}</div>}
+
+                        {children}
+
+                        {footerLinks && footerLinks.length > 0 && (
+                            <div className={styles.footer}>
+                                {footerLinks.map((link, i) => (
+                                    link.onClick ? (
+                                        <button key={i} onClick={link.onClick} className={styles.link}>
+                                            {link.label}
+                                        </button>
+                                    ) : link.href ? (
+                                        <a
+                                            key={i}
+                                            href={link.href}
+                                            onClick={(e) => handleLinkClick(e, link.href!)}
+                                            className={styles.link}
+                                        >
+                                            {link.label}
+                                        </a>
+                                    ) : null
+                                ))}
+                            </div>
+                        )}
+                    </>
+                )}
+            </div>
+        </div>
+    )
+}