完善前端项目结构和依赖配置

- 更新 package.json 中的依赖版本号，包括 element-plus、axios、pinia、vue-router 等
- 删除 HelloWorld 组件，替换为 router-view 以支持路由功能
- 添加 auth、category、customer、dashboard、medicine、role、stock、stockIn、stockOut、
  supplier、user 等多个 API 接口文件
- 创建权限指令、主布局组件和全局样式
- 集成 Element Plus UI 框架并注册图标组件
- 实现应用状态管理和用户状态管理 Store
- 配置 Vue Router 路由系统，支持动态菜单路由生成
- 移除旧的 CSS 样式文件，改用 SCSS 全局样式
```

frontend/src/views/login/LoginView.vue

@@ -0,0 +1,110 @@
+<script setup>
+import { ref, reactive } from 'vue'
+import { useRouter } from 'vue-router'
+import { useUserStore } from '@/stores/user'
+import { User, Lock } from '@element-plus/icons-vue'
+
+const router = useRouter()
+const userStore = useUserStore()
+
+const loginFormRef = ref(null)
+const loading = ref(false)
+const loginForm = reactive({
+  username: 'admin',
+  password: 'admin123',
+  remember: false,
+})
+
+const rules = {
+  username: [{ required: true, message: '请输入用户名', trigger: 'blur' }],
+  password: [{ required: true, message: '请输入密码', trigger: 'blur' }],
+}
+
+async function handleLogin() {
+  const valid = await loginFormRef.value.validate().catch(() => false)
+  if (!valid) return
+
+  loading.value = true
+  try {
+    await userStore.login({
+      username: loginForm.username,
+      password: loginForm.password,
+    })
+    router.push('/dashboard')
+  } catch {
+    // 错误已在拦截器中处理
+  } finally {
+    loading.value = false
+  }
+}
+</script>
+
+<template>
+  <div class="login-page">
+    <div class="login-card">
+      <h2 class="login-title">药品管理系统</h2>
+      <el-form
+        ref="loginFormRef"
+        :model="loginForm"
+        :rules="rules"
+        size="large"
+        @keyup.enter="handleLogin"
+      >
+        <el-form-item prop="username">
+          <el-input
+            v-model="loginForm.username"
+            placeholder="用户名"
+            :prefix-icon="User"
+          />
+        </el-form-item>
+        <el-form-item prop="password">
+          <el-input
+            v-model="loginForm.password"
+            type="password"
+            show-password
+            placeholder="密码"
+            :prefix-icon="Lock"
+          />
+        </el-form-item>
+        <el-form-item>
+          <el-checkbox v-model="loginForm.remember">记住我</el-checkbox>
+        </el-form-item>
+        <el-form-item>
+          <el-button
+            type="primary"
+            :loading="loading"
+            style="width: 100%"
+            @click="handleLogin"
+          >
+            {{ loading ? '登录中...' : '登 录' }}
+          </el-button>
+        </el-form-item>
+      </el-form>
+    </div>
+  </div>
+</template>
+
+<style lang="scss" scoped>
+.login-page {
+  height: 100vh;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  background: linear-gradient(135deg, #667eea 0%, #051f96 100%);
+}
+
+.login-card {
+  width: 420px;
+  padding: 40px;
+  background: #fff;
+  border-radius: 12px;
+  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.2);
+}
+
+.login-title {
+  text-align: center;
+  margin-bottom: 32px;
+  color: #303133;
+  font-size: 24px;
+}
+</style>