feat: 导入增强 + 客户合并 + 同伴自定义 + 性能优化

=== 导入系统全面增强 ===
- 5 Sheet 完整导入：拜访/计划/商机/要客/纪要
- 同访人智能解析：中英文逗号/顿号/分号 → 系统用户UUID + 外部人员TEXT
- 客户自动创建：Excel中不存在的客户自动入库
- 模糊名称匹配：去空格 + 包含关系纠错
- manager_id 修正：导入时用客户分配的经理（非Excel列/非导入人）
- 模板更新：Sheet5「客户经理」→「填报人」，同访人示例含逗号分隔

=== 客户合并功能 ===
- PUT 改名碰撞检测 → 409 + 合并预览
- GET merge-preview / POST merge 端点
- 事务级迁移：Visit/WorkPlan/MiniBusiness/KeyVisit/联系人/分配
- 去重逻辑：联系人(name+phone)、分配(manager+role)
- last_visit_date 取最大值

=== 拜访记录完善 ===
- visits 新增 companion_names TEXT[] 列
- 同访人支持自定义输入（外部人员），el-select allow-create
- 移动端 VisitForm + PC端 ManagerWorkspace 统一
- 周报「客户经理」→「相关人员」（创建人+同访人）
- 纪要「客户经理」→「填报人」
- 删除拜访后重新计算 customer.last_visit_date

=== 客户选择放开 ===
- 客户经理可看到全部客户（不再限自己分配的）
- 拜访时客户下拉返回全量

=== 前端性能优化 ===
- Element Plus 按需加载 (unplugin-vue-components + unplugin-element-plus)
- 周报照片URL并行请求 (Promise.all)
- onMounted 三路并行 (loadReport + dropdowns + AI)
- nginx Cache-Control: immutable for /assets/
- Google Fonts preconnect hints
- 图片上传前 Canvas 压缩 (max 1920px, quality 0.8)

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

frontend/src/views/desktop/ManagerWorkspace.vue

@@ -3,6 +3,7 @@ import { ref, onMounted, computed } from 'vue'
 import { ElMessage, ElMessageBox } from 'element-plus'
 import { todayStr } from '@/utils'
 import api from '@/api/index'
+import { compressImage } from '@/utils/image'
 import ImagePreview from '@/components/ImagePreview.vue'
 import EditLogPanel from '@/components/EditLogPanel.vue'
 
@@ -92,7 +93,7 @@ async function loadAll() {
 function openCreate(type: string) {
   dialogMode.value = 'create'; dialogType.value = type
   dialogTimeRange.value = null
-  if (type === 'visit') form.value = { customer_id: '', visit_date: todayStr(), visit_method: '上门', time_range: '', visitor_name: '', visitor_phone: '', communication_content: '', customer_demand: '' }
+  if (type === 'visit') form.value = { customer_id: '', visit_date: todayStr(), visit_method: '上门', time_range: '', visitor_name: '', visitor_phone: '', communication_content: '', customer_demand: '', companions: [], companion_names: [] }
   else if (type === 'note') form.value = { note_date: todayStr(), category: '其他', content: '', time_range: '' }
   else if (type === 'plan') form.value = { customer_id: '', plan_content: '', plan_date: todayStr(), status: '计划中' }
   else if (type === 'mini') form.value = { customer_id: '', product_type: '', amount: '', follow_up_detail: '', status: '跟进中', expected_revenue_date: '' }
@@ -134,11 +135,13 @@ async function handleDialogPhotoUpload(event: Event) {
   for (const file of Array.from(target.files)) {
     if ((form.value.photos || []).length >= 9) break
     try {
+      // Compress before upload to reduce storage & transfer
+      const compressed = await compressImage(file, { maxPixels: 1920, quality: 0.8 })
       // Get presigned URL
-      const presignRes = await api.post('/upload/presigned-url', null, { params: { filename: file.name, content_type: file.type || 'image/jpeg' } })
+      const presignRes = await api.post('/upload/presigned-url', null, { params: { filename: compressed.name, content_type: compressed.type || 'image/jpeg' } })
       // Upload directly to MinIO (not through our API)
       const axios = (await import('axios')).default
-      await axios.put(presignRes.data.upload_url, file, { headers: { 'Content-Type': file.type || 'image/jpeg' } })
+      await axios.put(presignRes.data.upload_url, compressed, { headers: { 'Content-Type': compressed.type || 'image/jpeg' } })
       const key = presignRes.data.object_key
       if (!form.value.photos) form.value.photos = []
       form.value.photos.push(key)
@@ -167,8 +170,23 @@ function removePhotoFromEdit(idx: number) {
   }
 }
 
+function splitCompanions(values: string[]) {
+  const uuidRe = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i
+  const sys: string[] = []; const ext: string[] = []
+  for (const v of (values || [])) {
+    if (uuidRe.test(v)) sys.push(v)
+    else if (v.trim()) ext.push(v.trim())
+  }
+  return { companions: sys, companion_names: ext }
+}
+
 async function handleSave() {
-  const t = dialogType.value; const d = form.value
+  const t = dialogType.value; let d = { ...form.value }
+  // Split companions for visit type
+  if (t === 'visit' && d.companions) {
+    const { companions, companion_names } = splitCompanions(d.companions)
+    d = { ...d, companions, companion_names }
+  }
   try {
     if (dialogMode.value === 'create') {
       switch (t) {
@@ -443,6 +461,11 @@ const notesByDate = computed(() => {
           </el-form-item>
           <el-form-item label="拜访人姓名"><el-input v-model="form.visitor_name" placeholder="实际拜访人姓名" /></el-form-item>
           <el-form-item label="拜访人电话"><el-input v-model="form.visitor_phone" placeholder="联系电话（可选）" /></el-form-item>
+          <el-form-item label="同访人员">
+            <el-select v-model="form.companions" multiple filterable allow-create default-first-option placeholder="选择或输入姓名（可多选）" style="width:100%">
+              <el-option v-for="u in allUsers" :key="u.id" :label="u.name" :value="u.id" />
+            </el-select>
+          </el-form-item>
           <el-form-item label="沟通内容"><el-input v-model="form.communication_content" type="textarea" :rows="3" /></el-form-item>
           <el-form-item label="客户需求"><el-input v-model="form.customer_demand" type="textarea" :rows="2" /></el-form-item>
           <el-form-item v-if="dialogMode === 'edit' && form.photos?.length" label="照片">