feat: implement WeChat MP OAuth login

- Add wechat-mp.service.ts for MP web authorization
- Add wechat-mp.routes.ts with /api/mp endpoints
- Update EntryQRCode.vue to show H5 URL QR code
- Update HomeView.vue with WeChat auth detection

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

packages/client-mobile/src/views/HomeView.vue

@@ -1,16 +1,120 @@
 <script setup lang="ts">
-import { onMounted } from 'vue';
-import { useRouter } from 'vue-router';
+import { ref, onMounted } from 'vue';
+import { useRouter, useRoute } from 'vue-router';
+import { showLoadingToast, closeToast, showToast } from 'vant';
 import { useConnectionStore } from '../stores/connection';
 
 const router = useRouter();
+const route = useRoute();
 const connectionStore = useConnectionStore();
 
-// Check if already logged in
-onMounted(() => {
+const isProcessing = ref(false);
+
+// API base URL
+const apiUrl = import.meta.env.VITE_API_URL || 'http://192.168.1.5:3000';
+
+/**
+ * 检测是否在微信环境中
+ */
+function isWechatBrowser(): boolean {
+  const ua = navigator.userAgent.toLowerCase();
+  return ua.includes('micromessenger');
+}
+
+/**
+ * 用code完成登录
+ */
+async function loginWithCode(code: string) {
+  isProcessing.value = true;
+  showLoadingToast({ message: '登录中...', forbidClick: true });
+
+  try {
+    const response = await fetch(`${apiUrl}/api/mp/login`, {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ code }),
+    });
+
+    const result = await response.json();
+    closeToast();
+
+    if (result.success && result.data) {
+      // 设置用户信息
+      connectionStore.setUser(
+        result.data.userId,
+        result.data.userName,
+        result.data.sessionToken
+      );
+
+      showToast({ message: '登录成功！', type: 'success' });
+
+      // 跳转到投票页面
+      router.replace('/vote');
+    } else {
+      showToast({ message: result.error || '登录失败', type: 'fail' });
+      isProcessing.value = false;
+    }
+  } catch (err) {
+    closeToast();
+    showToast({ message: '网络错误，请重试', type: 'fail' });
+    isProcessing.value = false;
+  }
+}
+
+/**
+ * 跳转到微信授权页面
+ */
+async function redirectToWechatAuth() {
+  try {
+    // 获取授权URL
+    const currentUrl = window.location.href.split('?')[0]; // 移除已有的query参数
+    const response = await fetch(
+      `${apiUrl}/api/mp/auth-url?redirect_uri=${encodeURIComponent(currentUrl)}&scope=snsapi_base`
+    );
+    const result = await response.json();
+
+    if (result.success && result.data?.authUrl) {
+      // 跳转到微信授权页面
+      window.location.href = result.data.authUrl;
+    } else {
+      console.error('[HomeView] Failed to get auth URL:', result.error);
+      showToast({ message: '获取授权链接失败', type: 'fail' });
+    }
+  } catch (err) {
+    console.error('[HomeView] Failed to redirect to auth:', err);
+    showToast({ message: '网络错误', type: 'fail' });
+  }
+}
+
+/**
+ * 处理微信授权流程
+ */
+async function handleWechatAuth() {
+  // 检查URL中是否有code参数（授权回调）
+  const code = route.query.code as string;
+
+  if (code) {
+    // 有code，用code完成登录
+    console.log('[HomeView] Got code from callback, logging in...');
+    await loginWithCode(code);
+  } else {
+    // 无code，跳转到授权页面
+    console.log('[HomeView] No code, redirecting to auth...');
+    await redirectToWechatAuth();
+  }
+}
+
+// 页面加载时检查登录状态和微信环境
+onMounted(async () => {
+  // 已登录则直接跳转
   if (connectionStore.userId && connectionStore.userName && connectionStore.userName !== '访客') {
-    // Already logged in, redirect to vote page
     router.replace('/vote');
+    return;
+  }
+
+  // 在微信环境中自动处理授权
+  if (isWechatBrowser()) {
+    await handleWechatAuth();
   }
 });
 </script>