feat(auth): implement user authentication and email verification

Add registration, login, and logout flows with session management
Integrate Resend for email verification tokens
Create frontend auth views and update topbar state

frontend/src/views/LoginView.vue

@@ -0,0 +1,71 @@
+<script setup lang="ts">
+import { ref } from 'vue';
+import { useRoute, useRouter } from 'vue-router';
+import { api, setAuthToken } from '../services/api';
+
+const route = useRoute();
+const router = useRouter();
+const email = ref('');
+const password = ref('');
+const busy = ref(false);
+const errorMessage = ref('');
+
+async function submitLogin() {
+  busy.value = true;
+  errorMessage.value = '';
+
+  try {
+    const response = await api.login({
+      email: email.value,
+      password: password.value
+    });
+    setAuthToken(response.token);
+
+    const redirect =
+      typeof route.query.redirect === 'string' && route.query.redirect.startsWith('/')
+        ? route.query.redirect
+        : '/pokemon';
+    await router.push(redirect);
+  } catch (error) {
+    errorMessage.value = error instanceof Error && error.message ? error.message : '登录失败';
+  } finally {
+    busy.value = false;
+  }
+}
+</script>
+
+<template>
+  <section class="auth-page">
+    <div class="auth-panel">
+      <div class="page-header">
+        <div>
+          <h1 class="page-title">登录</h1>
+          <p class="page-subtitle">使用已验证邮箱进入 Pokopia Wiki</p>
+        </div>
+      </div>
+
+      <form class="auth-form" @submit.prevent="submitLogin">
+        <div class="field">
+          <label for="login-email">邮箱</label>
+          <input id="login-email" v-model="email" autocomplete="email" required type="email" />
+        </div>
+
+        <div class="field">
+          <label for="login-password">密码</label>
+          <input id="login-password" v-model="password" autocomplete="current-password" required type="password" />
+        </div>
+
+        <p v-if="errorMessage" class="auth-message error">{{ errorMessage }}</p>
+
+        <button class="primary-button" :disabled="busy" type="submit">
+          {{ busy ? '登录中' : '登录' }}
+        </button>
+      </form>
+
+      <p class="auth-switch">
+        还没有账号？
+        <RouterLink to="/register">注册</RouterLink>
+      </p>
+    </div>
+  </section>
+</template>