refactor(auth): 管理端清除多身份残留(identities/currentIdentity/selectIdentity/Identity)

- auth.tsx/type 去 identities/currentIdentity 状态与 Identity 类型，role 恒取 user.role
- api/auth.ts 删 selectIdentity、getSavedUser/saveUser 去 identity 字段
- types.ts LoginResponse 去 identities/identity_id/port/identity_name 字段

Co-Authored-By: Claude <noreply@anthropic.com>

src/api/auth.ts

@@ -1,5 +1,5 @@
 import { api, setToken } from "@/api/client";
-import type { Identity, LoginResponse } from "@/types";
+import type { LoginResponse } from "@/types";
 
 export async function login(username: string, password: string): Promise<LoginResponse> {
   const res = await api.post<LoginResponse>("/auth/login", { username, password });
@@ -7,14 +7,6 @@ export async function login(username: string, password: string): Promise<LoginRe
   return res;
 }
 
-export async function selectIdentity(identityId: string): Promise<LoginResponse> {
-  const res = await api.post<LoginResponse>("/auth/select-identity", {
-    identity_id: identityId,
-  });
-  setToken(res.token);
-  return res;
-}
-
 // ---- 四种登录：短信验证码 / 微信扫码 / 小程序扫码 ----
 
 export async function sendCode(phone: string): Promise<{ sent: boolean; message: string; stub_code?: string }> {
@@ -64,7 +56,7 @@ export async function fetchMe(): Promise<Record<string, unknown>> {
   return api.get("/auth/me");
 }
 
-export function getSavedUser(): { username?: string; role?: string; identity?: Identity } | null {
+export function getSavedUser(): { username?: string; role?: string } | null {
   try {
     return JSON.parse(localStorage.getItem("@cloud-opc-admin/user") || "null");
   } catch {
@@ -72,7 +64,7 @@ export function getSavedUser(): { username?: string; role?: string; identity?: I
   }
 }
 
-export function saveUser(user: { username?: string; role?: string; identity?: Identity } | null) {
+export function saveUser(user: { username?: string; role?: string } | null) {
   if (user) localStorage.setItem("@cloud-opc-admin/user", JSON.stringify(user));
   else localStorage.removeItem("@cloud-opc-admin/user");
 }