Build fixes: offline-safe fonts, Next.js API route type updates, TS strict errors resolved, MUI import cleanup, chat markdown wrapper, Azure OpenAI typing, caching key + chapter API id types, and misc error-logging typings.

components/auth/auth-provider.tsx

@@ -4,18 +4,7 @@ import React, { createContext, useContext, useEffect, useState, ReactNode } from
 import { useLocale } from 'next-intl'
 import { useStore } from '@/lib/store'
 import { isTokenExpired, clearExpiredToken } from '@/lib/auth/client'
-
-interface User {
-  id: string
-  email: string
-  name?: string
-  role: string
-  theme: string
-  fontSize: string
-  createdAt: Date
-  updatedAt: Date
-  lastLoginAt?: Date
-}
+import type { User } from '@/types'
 
 interface AuthContextType {
   user: User | null
@@ -313,4 +302,4 @@ export function useAuth(): AuthContextType {
     throw new Error('useAuth must be used within an AuthProvider')
   }
   return context
-}
+}