feat(frontend): implement center auth session flow with route guard

src/lib/center-auth-client.ts

@@ -0,0 +1,40 @@
+import axios from 'axios'
+import { getRuntimeConfig } from './runtime-config'
+import type { AuthSession } from './auth-storage'
+
+export type LoginPayload = { email: string; password: string }
+
+type LoginResponse = {
+  accessToken: string
+  refreshToken: string
+  tokenType: string
+  user: { id: string; email: string }
+}
+
+type RefreshResponse = {
+  accessToken: string
+  refreshToken: string
+  tokenType: string
+}
+
+function centerClient() {
+  const cfg = getRuntimeConfig()
+  return axios.create({
+    baseURL: cfg.centerApiBase,
+    timeout: 10000,
+  })
+}
+
+export async function loginCenter(payload: LoginPayload): Promise<AuthSession> {
+  const res = await centerClient().post<LoginResponse>('/auth/login', payload)
+  return res.data
+}
+
+export async function refreshCenter(refreshToken: string): Promise<RefreshResponse> {
+  const res = await centerClient().post<RefreshResponse>('/auth/refresh', { refreshToken })
+  return res.data
+}
+
+export async function logoutCenter(refreshToken: string): Promise<void> {
+  await centerClient().post('/auth/logout', { refreshToken })
+}