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/AuthFormPage.tsx

@@ -0,0 +1,127 @@
+'use client'
+
+import { useState, ReactNode } from 'react'
+import { useAllauthAPI } from '../contexts/APIContext'
+import { useStyles } from '../contexts/StylesContext'
+import useAuthForm, { AuthField } from './AuthForm'
+import { AuthResponse, AuthDetails } from '../api'
+
+interface FieldConfig {
+    name: string
+    title: string
+    type: string
+    placeholder?: string
+}
+
+interface FooterLink {
+    href: string
+    label: string
+}
+
+interface AuthFormPageProps {
+    title: string
+    subtitle?: string
+    fields: FieldConfig[]
+    submitLabel?: string
+    submittingLabel?: string
+    submitFn: (api: ReturnType<typeof useAllauthAPI>, data: Record<string, string>) => Promise<AuthResponse>
+    onResponse: (response: AuthResponse, authDetails: AuthDetails, data: Record<string, string>) => void
+    footerLinks?: FooterLink[]
+    preFields?: ReactNode
+    postFields?: ReactNode
+    error?: string | null
+}
+
+export function AuthFormPage({
+    title,
+    subtitle,
+    fields,
+    submitLabel = 'Submit',
+    submittingLabel = 'Submitting...',
+    submitFn,
+    onResponse,
+    footerLinks,
+    preFields,
+    postFields,
+    error: externalError,
+}: AuthFormPageProps) {
+    const api = useAllauthAPI()
+    const styles = useStyles()
+
+    const [data, setData] = useState<Record<string, string>>(() =>
+        Object.fromEntries(fields.map(f => [f.name, '']))
+    )
+
+    const authForm = useAuthForm(
+        () => submitFn(api, data),
+        (response, authDetails) => onResponse(response, authDetails, data)
+    )
+
+    const handleSubmit = (e: React.FormEvent) => {
+        e.preventDefault()
+        authForm.submit()
+    }
+
+    const handleFieldChange = (fieldName: string) => (e: React.ChangeEvent<HTMLInputElement>) => {
+        setData(prev => ({ ...prev, [fieldName]: e.target.value }))
+    }
+
+    const formErrors = authForm.errors.filter(err => !err.param || err.param === '__all__')
+
+    return (
+        <div className={styles.container}>
+            <div className={styles.card}>
+                <h1 className={styles.title}>{title}</h1>
+                {subtitle && <p className={styles.subtitle}>{subtitle}</p>}
+
+                {externalError && <p className={styles.error}>{externalError}</p>}
+                {formErrors.length > 0 && (
+                    <div className={styles.error}>
+                        {formErrors.map((err, i) => (
+                            <p key={i}>{err.message}</p>
+                        ))}
+                    </div>
+                )}
+
+                <form onSubmit={handleSubmit} className={styles.form} suppressHydrationWarning>
+                    {preFields}
+
+                    <div className={styles.fieldsContainer}>
+                        {fields.map(field => (
+                            <AuthField
+                                key={field.name}
+                                title={field.title}
+                                name={field.name}
+                                type={field.type}
+                                init={data[field.name]}
+                                onChange={handleFieldChange(field.name)}
+                                authErrors={authForm.errors}
+                                placeholder={field.placeholder}
+                            />
+                        ))}
+                    </div>
+
+                    {postFields}
+
+                    <button
+                        type="submit"
+                        className={styles.submit}
+                        disabled={authForm.fetching}
+                    >
+                        {authForm.fetching ? submittingLabel : submitLabel}
+                    </button>
+                </form>
+
+                {footerLinks && footerLinks.length > 0 && (
+                    <div className={styles.footer}>
+                        {footerLinks.map((link, i) => (
+                            <a key={i} href={link.href} className={styles.link}>
+                                {link.label}
+                            </a>
+                        ))}
+                    </div>
+                )}
+            </div>
+        </div>
+    )
+}