feat(pl): show brand constraint on plan product rows

Co-authored-by: Cursor <cursoragent@cursor.com>

web-admin/src/components/business/pl-plan-form-dialog/PlPlanFormProductTable.vue

@@ -8,6 +8,15 @@
             <PlProductNameHazardCell :product="row" />
           </template>
         </el-table-column>
+        <el-table-column label="品牌约定" min-width="110" align="center">
+          <template #default="{ row }">
+            <el-tag v-if="row.brandMode === 'required'" size="small" type="warning">
+              {{ row.brandName || '指定品牌' }}
+            </el-tag>
+            <el-tag v-else-if="row.brandMode === 'any'" size="small" type="info">不限</el-tag>
+            <span v-else>—</span>
+          </template>
+        </el-table-column>
         <el-table-column label="型号/规格" min-width="120" show-overflow-tooltip>
           <template #default="{ row }">
             {{ row.model || row.productModel || '—' }}