feat: 添加身份一致性检查，更新登录逻辑以清除不一致的缓存

frontend/src/app/pages/LoginPage.tsx

@@ -3,7 +3,7 @@ import { useNavigate } from "react-router";
 import { motion } from "motion/react";
 import { Heart } from "lucide-react";
 import { useUser } from "../context/UserContext";
-import { devLogin, fetchApi } from "../services/api";
+import { devLogin, fetchApi, getToken, clearToken, decodeToken } from "../services/api";
 import { debugLog, clearDebugLogs } from "../services/debug";
 
 export function LoginPage() {
@@ -14,6 +14,21 @@ export function LoginPage() {
   useEffect(() => {
     clearDebugLogs();
 
+    // 身份一致性检查：URL 中的 openid 与缓存 token 不一致时清除缓存
+    const urlOpenid = new URLSearchParams(window.location.search).get('openid');
+    const cachedToken = getToken();
+    if (urlOpenid && cachedToken) {
+      try {
+        const payload = decodeToken(cachedToken);
+        if (payload.openid !== urlOpenid) {
+          debugLog(`[auth] openid 不一致: URL=${urlOpenid}, cache=${payload.openid}，清除缓存`);
+          clearToken();
+        }
+      } catch (e) {
+        debugLog(`[auth] token 解码失败: ${e}`);
+      }
+    }
+
     const params = new URLSearchParams(window.location.search);
     debugLog(`URL: ${window.location.href.substring(0, 100)}`);
     debugLog(`search: ${window.location.search}`);