feat: 双主题系统 — 编辑风 + 极简亮色

前端:
- 新增 Pinia theme store，localStorage 持久化，data-theme 切换
- App.vue: :root 新增 --font-*/--sidebar-* CSS 变量；新增 :root[data-theme=light] 完整配色（极简黑白金 + Noto Sans SC）
- DesktopLayout: 侧边栏 15 个变量化 + 顶栏主题切换按钮
- MobileLayout: 装饰色变量化
- Settings: 新增「界面主题」卡片
- 21 个组件 font-family 统一替换为 var(--font-*)
- 新增 utils/managerColor.ts — 12 色调色板 + 自适应文字色 + 后端自定义色优先
- WorkPlans/MiniBusiness/KeyVisits/CustomerManage: 客户经理标签色统一走共享工具
- UserManage: 编辑弹窗新增颜色选择器（仅 manager）
- LightBoard: 去标题星标图标
- ManagerWorkspace/WorkPlans/MiniBusiness/KeyVisits: 删除按钮改为实心红底白字

后端:
- User 模型新增 color 列 + lifespan 自动迁移
- users API 支持 color 字段读写
- UserOut schema 新增 color

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

frontend/src/views/desktop/CustomerManage.vue

@@ -1,11 +1,15 @@
 <script setup lang="ts">
-import { ref, onMounted } from 'vue'
+import { ref, computed, onMounted } from 'vue'
 import { useAuthStore } from '@/stores/auth'
+import { useThemeStore } from '@/stores/theme'
 import { customersApi } from '@/api/customers'
 import { ElMessage, ElMessageBox } from 'element-plus'
+import { getManagerColor as mgrColorFn, getMgrTextColor, loadManagerColors } from '@/utils/managerColor'
 import api from '@/api/index'
 
 const auth = useAuthStore()
+const themeStore = useThemeStore()
+const isLight = computed(() => themeStore.currentTheme === 'light')
 const loading = ref(false)
 const search = ref('')
 const filterIndustry = ref('')
@@ -43,7 +47,7 @@ const importLoading = ref(false)
 const importResult = ref<any>(null)
 
 onMounted(async () => {
-  await loadCustomers()
+  await Promise.all([loadCustomers(), loadManagerColors()])
   try {
     const res = await api.get('/users/')
     managers.value = (res.data || []).filter((u: any) => u.role !== 'leader')
@@ -193,11 +197,11 @@ async function removeExistingContact(contactId: string) {
   } catch (e: any) { if (e !== 'cancel') ElMessage.error('删除失败') }
 }
 
-const mgrColors = ['#1C3738','#4A6741','#5B7FA5','#7B7568','#8B6F47','#6B5B4F','#3D5A5C','#5C4A3D']
 function mgrColor(name: string) {
-  if (!name) return '#909399'
-  let h = 0; for (let i=0;i<name.length;i++) h = name.charCodeAt(i) + ((h<<5)-h)
-  return mgrColors[Math.abs(h) % mgrColors.length]
+  return mgrColorFn(name, isLight.value)
+}
+function mgrTextColor(name: string) {
+  return getMgrTextColor(mgrColor(name))
 }
 
 async function openDetail(customer: any) {
@@ -339,7 +343,7 @@ async function handleImport() {
         <el-table-column prop="in_use_services" label="在用业务" min-width="150" />
         <el-table-column label="客户经理" width="90">
           <template #default="{ row }">
-            <el-tag :color="mgrColor(row.primary_manager_name)" effect="dark" size="small" style="border:none;color:#fff">{{ row.primary_manager_name || '-' }}</el-tag>
+            <el-tag :color="mgrColor(row.primary_manager_name)" effect="dark" size="small" :style="{ border:'none', color: mgrTextColor(row.primary_manager_name) }">{{ row.primary_manager_name || '-' }}</el-tag>
           </template>
         </el-table-column>
       </el-table>
@@ -410,7 +414,7 @@ async function handleImport() {
           <el-descriptions-item label="备注">{{ detailCustomer.remarks || '-' }}</el-descriptions-item>
           <el-descriptions-item label="客户经理">{{ detailCustomer.primary_manager_name || '-' }}</el-descriptions-item>
         </el-descriptions>
-        <h4 style="margin-top:16px; font-family: 'ZCOOL XiaoWei', STSong, serif; color: var(--ink)">联系人</h4>
+        <h4 style="margin-top:16px; font-family: var(--font-heading); color: var(--ink)">联系人</h4>
         <div v-if="detailCustomer.contacts?.length">
           <el-tag v-for="c in detailCustomer.contacts" :key="c.id" style="margin:4px">
             {{ c.name }}{{ c.phone ? ' · '+c.phone : '' }}{{ c.role_desc ? ' ('+c.role_desc+')' : '' }}
@@ -489,7 +493,7 @@ async function handleImport() {
 .page-head-row { display: flex; justify-content: space-between; align-items: center; }
 .page-title {
   margin: 0;
-  font-family: 'ZCOOL XiaoWei', STSong, serif;
+  font-family: var(--font-heading);
   font-size: 22px; font-weight: 400;
   color: var(--ink); letter-spacing: 0.06em;
 }