feat(web): 正式提取流程设计能力到AI目录下，做代码拆分

service-web/client/src/pages/ai/flow/node/StartNode.tsx

@@ -0,0 +1,50 @@
+import type {NodeProps} from '@xyflow/react'
+import AmisNode from './AmisNode.tsx'
+
+const StartNode = (props: NodeProps) => AmisNode(
+  props,
+  'start',
+  '开始节点',
+  '定义输入变量',
+  [
+    {
+      type: 'input-kvs',
+      name: 'fields',
+      addButtonText: '新增入参',
+      draggable: false,
+      keyItem: {
+        label: '参数名称',
+      },
+      valueItems: [
+        {
+          type: 'input-text',
+          name: 'description',
+          label: '参数描述',
+        },
+        {
+          type: 'select',
+          name: 'type',
+          label: '参数类型',
+          required: true,
+          selectFirst: true,
+          options: [
+            {
+              label: '文本',
+              value: 'text',
+            },
+            {
+              label: '数字',
+              value: 'number',
+            },
+            {
+              label: '文件',
+              value: 'files',
+            },
+          ],
+        },
+      ],
+    },
+  ],
+)
+
+export default StartNode