Feat: Let system variables appear in operator prompts #3221 (#8154)

### What problem does this PR solve?
Feat: Let system variables appear in operator prompts #3221

### Type of change


- [x] New Feature (non-breaking change which adds functionality)

web/src/pages/agent/form/agent-form/constant.ts

@@ -1,4 +0,0 @@
-export enum PromptRole {
-  User = 'user',
-  Assistant = 'assistant',
-}

web/src/pages/agent/form/agent-form/dynamic-prompt.tsx

@@ -11,8 +11,8 @@ import { X } from 'lucide-react';
 import { memo } from 'react';
 import { useFieldArray, useFormContext } from 'react-hook-form';
 import { useTranslation } from 'react-i18next';
+import { PromptRole } from '../../constant';
 import { PromptEditor } from '../components/prompt-editor';
-import { PromptRole } from './constant';
 
 const options = [
   { label: 'User', value: PromptRole.User },

web/src/pages/agent/form/agent-form/use-watch-change.ts

@@ -1,7 +1,7 @@
 import { useEffect } from 'react';
 import { UseFormReturn, useWatch } from 'react-hook-form';
+import { PromptRole } from '../../constant';
 import useGraphStore from '../../store';
-import { PromptRole } from './constant';
 
 export function useWatchFormChange(id?: string, form?: UseFormReturn) {
   let values = useWatch({ control: form?.control });