feat: 前后端全量开发 v0.2

后端:
- 客户模块 CRUD+搜索 (api/services/repositories 分层)
- 合同模块: FG单号规则/意向单转正式单/订单创建自动快照客户信息
- 优化下料: FFD首递减装箱算法(利用率统计/余料/未排入清单)
前端 (Vue3+TS+Element Plus):
- 7页面: 登录/工作台/订单中心/合同/客户/样板库/优化下料
- 自研二维窗型画布渲染器: 解析drawing_data渲染玻璃区域/外框/
  扇开向标记/尺寸标注, 支持缩放平移复位
- 样板库与订单联动(用此样板下单自动带图纸)
- axios统一envelope拦截/登录守卫/付费墙提示
工程:
- SPA history 回退路由, 构建产物挂载后端
- 全接口回归 6/6 通过

frontend/src/views/CustomersView.vue

@@ -0,0 +1,89 @@
+<template>
+  <el-card>
+    <div class="toolbar">
+      <el-input v-model="keyword" placeholder="姓名/电话/地址" clearable style="width:240px" @keyup.enter="load" />
+      <el-button type="primary" @click="load">查询</el-button>
+      <div style="flex:1" />
+      <el-button type="primary" plain @click="openEdit()">新增客户</el-button>
+    </div>
+    <el-table :data="rows" v-loading="loading" stripe>
+      <el-table-column prop="id" label="ID" width="70" />
+      <el-table-column prop="name" label="姓名" min-width="120" />
+      <el-table-column prop="phone" label="电话" width="140" />
+      <el-table-column prop="address" label="地址" min-width="180" />
+      <el-table-column prop="salesmen" label="业务员" width="100" />
+      <el-table-column prop="created_at" label="创建时间" width="170" />
+      <el-table-column label="操作" width="140" fixed="right">
+        <template #default="{ row }">
+          <el-button size="small" @click="openEdit(row)">编辑</el-button>
+          <el-button size="small" type="danger" plain @click="remove(row)">删</el-button>
+        </template>
+      </el-table-column>
+    </el-table>
+    <el-pagination style="margin-top:12px; justify-content:flex-end" background layout="total, prev, pager, next"
+                   :total="total" :page-size="page_size" v-model:current-page="page" @current-change="load" />
+
+    <el-dialog v-model="editVisible" :title="form.id ? '编辑客户' : '新增客户'" width="480px">
+      <el-form :model="form" label-width="70px">
+        <el-form-item label="姓名"><el-input v-model="form.name" /></el-form-item>
+        <el-form-item label="电话"><el-input v-model="form.phone" /></el-form-item>
+        <el-form-item label="地址"><el-input v-model="form.address" /></el-form-item>
+        <el-form-item label="备注"><el-input v-model="form.note" type="textarea" /></el-form-item>
+      </el-form>
+      <template #footer>
+        <el-button @click="editVisible = false">取消</el-button>
+        <el-button type="primary" @click="save">保存</el-button>
+      </template>
+    </el-dialog>
+  </el-card>
+</template>
+
+<script setup lang="ts">
+import { onMounted, reactive, ref } from 'vue'
+import { ElMessage, ElMessageBox } from 'element-plus'
+import { api } from '../api'
+
+const rows = ref<any[]>([])
+const total = ref(0)
+const page = ref(1)
+const page_size = 15
+const keyword = ref('')
+const loading = ref(false)
+const editVisible = ref(false)
+const form = reactive({ id: 0, name: '', phone: '', address: '', note: '' })
+
+async function load() {
+  loading.value = true
+  try {
+    const d = await api<any>('get', `/api/customers?page=${page.value}&page_size=${page_size}&keyword=${keyword.value}`)
+    rows.value = d.data
+    total.value = d.total
+  } finally { loading.value = false }
+}
+
+function openEdit(row?: any) {
+  Object.assign(form, { id: row?.id ?? 0, name: row?.name ?? '', phone: row?.phone ?? '', address: row?.address ?? '', note: row?.note ?? '' })
+  editVisible.value = true
+}
+
+async function save() {
+  if (form.id) await api('put', `/api/customers/${form.id}`, form)
+  else await api('post', '/api/customers', form)
+  ElMessage.success('已保存')
+  editVisible.value = false
+  load()
+}
+
+async function remove(row: any) {
+  await ElMessageBox.confirm(`确定删除客户「${row.name}」?`, '提示', { type: 'warning' })
+  await api('delete', `/api/customers/${row.id}`)
+  ElMessage.success('已删除')
+  load()
+}
+
+onMounted(load)
+</script>
+
+<style scoped>
+.toolbar { display: flex; gap: 10px; margin-bottom: 12px; }
+</style>