feat: KPI细条新增两项完成率 + 侧边菜单加两个占位项

frontend/src/components/Layout/SideNav.css

@@ -36,3 +36,27 @@
   background: var(--color-accent-green) !important;
   color: var(--color-primary-green) !important;
 }
+
+/* disabled 项整体灰化 + 不可点击 */
+.side-nav-menu .ant-menu-item-disabled {
+  opacity: 0.55;
+  cursor: not-allowed !important;
+}
+
+/* 即将上线小标签 */
+.menu-soon-tag {
+  font-size: 10px;
+  color: #999;
+  background: #f0f0f0;
+  padding: 1px 5px;
+  border-radius: 4px;
+  margin-left: 6px;
+  vertical-align: middle;
+  white-space: nowrap;
+}
+
+/* disabled 项内标签不受 opacity 影响 */
+.side-nav-menu .ant-menu-item-disabled .menu-soon-tag {
+  opacity: 1;
+  color: #888;
+}

frontend/src/components/Layout/SideNav.jsx

@@ -7,6 +7,7 @@ import {
   SyncOutlined,
   UserOutlined,
   TeamOutlined,
+  SoundOutlined,
 } from '@ant-design/icons'
 import useAuthStore from '../../stores/authStore'
 
@@ -23,6 +24,28 @@ function SideNav() {
     { key: '/doco', icon: <SyncOutlined />, label: '文稿对齐' },
     { key: '/editor-home', icon: <UserOutlined />, label: '个人首页' },
     { key: '/users', icon: <TeamOutlined />, label: '用户管理' },
+    {
+      key: 'tts-placeholder',
+      icon: <SoundOutlined />,
+      label: (
+        <span className="menu-item-with-tag">
+          蓝皓配音 TTS 2.0
+          <span className="menu-soon-tag">即将上线</span>
+        </span>
+      ),
+      disabled: true,
+    },
+    {
+      key: 'collab-placeholder',
+      icon: <TeamOutlined />,
+      label: (
+        <span className="menu-item-with-tag">
+          内部协作（Mattermost）
+          <span className="menu-soon-tag">即将上线</span>
+        </span>
+      ),
+      disabled: true,
+    },
   ]
 
   // 按角色过滤菜单项

frontend/src/pages/Dashboard/Dashboard.jsx

@@ -7,6 +7,8 @@ import {
   BarChartOutlined,
   PictureOutlined,
   UploadOutlined,
+  TargetOutlined,
+  AimOutlined,
 } from '@ant-design/icons'
 import useAuthStore from '../../stores/authStore'
 import { listEpisodes } from '../../services/episodeService'
@@ -54,6 +56,32 @@ function getShortTitle(title) {
   return title.length > 9 ? title.slice(0, 9) + '...' : title
 }
 
+/**
+ * 计算当年完成率（纯前端，量纲已确认为 0~1 小数直接相除）
+ * - "当年"= 当前自然年（new Date().getFullYear()）
+ * - avg(audience_share) 当年已录期 ÷ base/stretch_target
+ * - 无数据时始终返回 { base: '—', stretch: '—' }
+ * - 完成率可 >100% 正常显示
+ */
+function calcCompletionRate(episodes, targets) {
+  const yearInt = new Date().getFullYear()
+  const yearEpisodes = episodes.filter(e => {
+    const airYear = new Date(e.air_date).getFullYear()
+    return airYear === yearInt && e.audience_share != null
+  })
+  const target = (targets || []).find(t => Number(t.year) === yearInt)
+
+  if (!yearEpisodes.length || !target) return { base: '—', stretch: '—' }
+
+  const avgShare = yearEpisodes.reduce((sum, e) => sum + Number(e.audience_share), 0) / yearEpisodes.length
+  const baseRate = avgShare / Number(target.base_target)
+  const stretchRate = avgShare / Number(target.stretch_target)
+  return {
+    base: (baseRate * 100).toFixed(1) + '%',
+    stretch: (stretchRate * 100).toFixed(1) + '%',
+  }
+}
+
 function Dashboard() {
   const { user } = useAuthStore()
   const [episodes, setEpisodes] = useState([])
@@ -95,7 +123,8 @@ function Dashboard() {
     setCoverModalOpen(false)
   }
 
-  // KPI 数据
+  // KPI 数据（扩为 5 项：原有 3 项 + 年度完成率 2 项）
+  const completion = calcCompletionRate(episodes, targets)
   const kpiData = [
     {
       icon: <EyeOutlined style={{ color: '#6b8e6b', fontSize: 14 }} />,
@@ -115,6 +144,18 @@ function Dashboard() {
       label: '年度目标',
       value: targets.length || '--',
     },
+    {
+      icon: <TargetOutlined style={{ color: '#7b5e9e', fontSize: 14 }} />,
+      bg: '#f3e5f5',
+      label: '基础目标完成率',
+      value: completion.base,
+    },
+    {
+      icon: <AimOutlined style={{ color: '#c0584f', fontSize: 14 }} />,
+      bg: '#fce4ec',
+      label: '摸高目标完成率',
+      value: completion.stretch,
+    },
   ]
 
   return (