feat(crm): entity_select + kanban + 级联过滤声明

- PluginField 新增 ref_label_field / ref_search_fields / cascade_from / cascade_filter 字段
- PluginPageType 新增 Kanban 变体（lane_field / lane_order / card_title_field / card_subtitle_field / card_fields / enable_drag）
- CRM plugin.toml: contact.customer_id 和 communication.contact_id 添加 entity_select 声明
- CRM plugin.toml: communication.contact_id 添加 cascade_from/cascade_filter 级联过滤
- CRM plugin.toml: 新增销售漏斗 kanban 页面声明
- 新增 5 个解析测试（entity_select / cascade / kanban / 空值校验）

crates/erp-plugin-crm/plugin.toml

@@ -181,6 +181,9 @@ display_name = "联系人"
   field_type = "uuid"
   required = true
   display_name = "所属客户"
+  ui_widget = "entity_select"
+  ref_label_field = "name"
+  ref_search_fields = ["name", "code"]
 
   [[schema.entities.fields]]
   name = "name"
@@ -238,6 +241,11 @@ display_name = "沟通记录"
   name = "contact_id"
   field_type = "uuid"
   display_name = "关联联系人"
+  ui_widget = "entity_select"
+  ref_label_field = "name"
+  ref_search_fields = ["name"]
+  cascade_from = "customer_id"
+  cascade_filter = "customer_id"
 
   [[schema.entities.fields]]
   name = "type"
@@ -432,3 +440,15 @@ node_label_field = "name"
 type = "dashboard"
 label = "统计概览"
 icon = "DashboardOutlined"
+
+[[ui.pages]]
+type = "kanban"
+entity = "customer"
+label = "销售漏斗"
+icon = "swap"
+lane_field = "level"
+lane_order = ["potential", "normal", "vip", "svip"]
+card_title_field = "name"
+card_subtitle_field = "code"
+card_fields = ["region", "status"]
+enable_drag = true