feat: Hide the upload button in the external agent's chat box #1880 (#1984)

### What problem does this PR solve?

feat: Hide the upload button in the external agent's chat box  #1880

### Type of change


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

web/src/constants/chat.ts

@@ -10,3 +10,8 @@ export const variableEnabledFieldMap = {
   frequencyPenaltyEnabled: 'frequency_penalty',
   maxTokensEnabled: 'max_tokens',
 };
+
+export enum SharedFrom {
+  Agent = 'agent',
+  Chat = 'chat',
+}