feat(auth): add admin bootstrap and username login

Initialize admin bootstrap settings during startup, persist username support in auth flows, and align frontend auth requests with local API behavior.

frontend/src/api/index.ts

@@ -3,7 +3,7 @@ import axios from 'axios'
 let redirectingToLogin = false
 
 const api = axios.create({
-  baseURL: import.meta.env.VITE_API_URL,
+  baseURL: import.meta.env.DEV ? '' : import.meta.env.VITE_API_URL,
   timeout: 30000,
 })
 

frontend/src/stores/auth.ts

@@ -6,16 +6,16 @@ let unauthorizedListenerRegistered = false
 
 export const useAuthStore = defineStore('auth', () => {
   const token = ref<string | null>(localStorage.getItem('access_token'))
-  const user = ref<{ id: string; email: string; full_name?: string } | null>(null)
+  const user = ref<{ id: string; username: string; email: string; full_name?: string } | null>(null)
   const isAuthReady = ref(false)
   const isFetchingUser = ref(false)
   let authReadyPromise: Promise<void> | null = null
 
   const isAuthenticated = computed(() => !!token.value)
 
-  async function login(email: string, password: string) {
+  async function login(identifier: string, password: string) {
     const formData = new FormData()
-    formData.append('username', email)
+    formData.append('username', identifier)
     formData.append('password', password)
     const response = await api.post('/api/auth/login', formData, {
       headers: { 'Content-Type': 'multipart/form-data' },