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/AuthForm.tsx

@@ -0,0 +1,99 @@
+'use client'
+
+import { ReactNode, useState, useEffect } from 'react'
+import { AuthDetails, AuthError, AuthResponse, getAuthDetails } from '../api'
+import { useAuthContext } from '../contexts/AuthContext'
+import { useStyles } from '../contexts/StylesContext'
+
+interface AuthForm {
+    submit: () => void
+    authDetails: AuthDetails
+    fetching: boolean
+    response: AuthResponse | null
+    errors: AuthError[]
+}
+
+export default function useAuthForm(
+    submissionAction: () => Promise<AuthResponse>,
+    responseAction?: (response: AuthResponse, authDetails: AuthDetails) => void,
+): AuthForm {
+    const auth = useAuthContext().auth
+    const [fetching, setFetching] = useState<boolean>(false)
+    const [response, setResponse] = useState<AuthResponse | null>(null)
+    const [errors, setErrors] = useState<AuthError[]>([])
+    const [authDetails, setAuthDetails] = useState<AuthDetails>(getAuthDetails(auth))
+
+    function submit() {
+        setFetching(true)
+        submissionAction()
+            .then((r) => {
+                setResponse(r)
+                setErrors(r.errors || [])
+                setFetching(false)
+                if (r && responseAction) {
+                    responseAction(r, authDetails)
+                }
+                setAuthDetails(getAuthDetails(auth))
+            })
+            .catch((e) => {
+                console.error(e)
+                setFetching(false)
+            })
+    }
+
+    return { submit, authDetails, fetching, response, errors }
+}
+
+interface AuthFieldProps {
+    title: string
+    name: string
+    type: string
+    init: string
+    onChange: (e: React.ChangeEvent<HTMLInputElement>) => void
+    authErrors: AuthError[]
+    placeholder?: string
+    children?: ReactNode
+}
+
+export function AuthField({
+    title,
+    name,
+    type,
+    init,
+    onChange,
+    authErrors,
+    placeholder,
+    children,
+}: AuthFieldProps) {
+    const styles = useStyles()
+    const [mounted, setMounted] = useState(false)
+    const fieldErrors = authErrors.filter(err => err.param === name)
+
+    useEffect(() => {
+        setMounted(true)
+    }, [])
+
+    return (
+        <div className={styles.field}>
+            <label className={styles.fieldLabel}>{title}</label>
+            {mounted ? (
+                <input
+                    type={type}
+                    value={init}
+                    onChange={onChange}
+                    placeholder={placeholder}
+                    className={styles.fieldInput}
+                    autoComplete="off"
+                />
+            ) : (
+                <div className={styles.fieldInput} style={{ minHeight: '2.75rem' }} />
+            )}
+            {fieldErrors.map((err, i) => (
+                <p key={i} className={styles.fieldError}>{err.message}</p>
+            ))}
+            {children}
+        </div>
+    )
+}
+
+