feat: 优化登录页面和工作台功能

- 新增教师端评价体系文档下载功能
  * 添加"评价体系说明"模块卡片到Dashboard工作台
  * 实现评价体系.xlsx文件下载功能
  * 文件移至public目录，支持生产环境部署

- 调整登录页面快速体验按钮
  * 教师登录按钮移至第一位
  * 禁用学生登录按钮（灰色不可点击）
  * 保留学生能力评价画像按钮可用

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/views/Dashboard.vue

@@ -217,6 +217,41 @@
           </div>
         </div>
 
+        <div
+          v-if="user?.role === 'teacher'"
+          class="module-card"
+          @click="downloadEvaluationSystem"
+        >
+          <div class="module-accent primary" />
+          <div class="module-header">
+            <div class="module-icon-wrapper">
+              <div class="module-icon primary">
+                <Document :size="18" />
+              </div>
+            </div>
+            <div class="module-badge special">
+              教师专属
+            </div>
+          </div>
+          <div class="module-content">
+            <h3 class="module-title">
+              评价体系说明
+            </h3>
+            <p class="module-description">
+              下载完整的实践教学评价体系说明文档，包含评价维度、指标定义、评分标准等详细内容。
+            </p>
+            <div class="module-features">
+              <span class="feature-tag">评价维度</span>
+              <span class="feature-tag">指标体系</span>
+              <span class="feature-tag">评分标准</span>
+            </div>
+            <div class="module-footer">
+              <span class="module-action">下载文档</span>
+              <ArrowRight :size="14" />
+            </div>
+          </div>
+        </div>
+
         <div
           class="module-card active"
           @click="navigateToReport"
@@ -385,12 +420,20 @@ export default {
       router.push('/home/upload')
     }
 
+    const downloadEvaluationSystem = () => {
+      const link = document.createElement('a')
+      link.href = '/评价体系.xlsx'
+      link.download = '实践教学评价体系说明.xlsx'
+      link.click()
+    }
+
     return {
       user,
       goToEvaluate,
       goToPortrait,
       goToUpload,
-      navigateToReport
+      navigateToReport,
+      downloadEvaluationSystem
     }
   }
 }

src/views/Login.vue

@@ -152,15 +152,6 @@
               <span>快速体验</span>
             </div>
             <div class="demo-buttons">
-              <button
-                class="demo-btn student-btn"
-                @click="quickLogin('student')"
-              >
-                <el-icon class="demo-icon">
-                  <User />
-                </el-icon>
-                学生登录
-              </button>
               <button
                 class="demo-btn teacher-btn"
                 @click="quickLogin('teacher')"
@@ -170,6 +161,15 @@
                 </el-icon>
                 教师登录
               </button>
+              <button
+                class="demo-btn student-btn"
+                disabled
+              >
+                <el-icon class="demo-icon">
+                  <User />
+                </el-icon>
+                学生登录
+              </button>
             </div>
             <div class="demo-buttons portrait-section">
               <button
@@ -539,6 +539,36 @@ export default {
   margin-top: var(--spacing-xs);
 }
 
+.demo-btn:disabled {
+  background: var(--gray-lighter);
+  color: var(--text-disabled);
+  border-color: var(--border);
+  cursor: not-allowed;
+  opacity: 0.6;
+}
+
+.demo-btn:disabled:hover {
+  background: var(--gray-lighter);
+  color: var(--text-disabled);
+  border-color: var(--border);
+  transform: none;
+  box-shadow: none;
+}
+
+.big-screen-btn:disabled {
+  background: var(--gray-lighter) !important;
+  color: var(--text-disabled) !important;
+  border-color: var(--border) !important;
+}
+
+.big-screen-btn:disabled:hover {
+  background: var(--gray-lighter) !important;
+  color: var(--text-disabled) !important;
+  border-color: var(--border) !important;
+  transform: none;
+  box-shadow: none;
+}
+
 .login-footer {
   text-align: center;
 }