Show tool execution messages in AI agent chat (#13117)

https://github.com/user-attachments/assets/c0a42726-50ac-496e-a993-9d6076a84a6a

---------

Co-authored-by: Félix Malfait <felix@twenty.com>

packages/twenty-front/src/modules/apollo/utils/streamingRestLink.ts

@@ -1,4 +1,9 @@
-import { ApolloLink, Observable, Operation } from '@apollo/client/core';
+import {
+  ApolloLink,
+  Observable,
+  Operation,
+  ServerError,
+} from '@apollo/client/core';
 import { FetchResult } from '@apollo/client/link/core';
 import { ArgumentNode, DirectiveNode } from 'graphql';
 import { isDefined } from 'twenty-shared/utils';
@@ -57,7 +62,13 @@ export class StreamingRestLink extends ApolloLink {
       fetch(url, requestConfig)
         .then(async (response) => {
           if (!response.ok) {
-            throw new Error(`HTTP error! status: ${response.status}`);
+            const networkError = new Error(
+              `HTTP error! status: ${response.status}`,
+            ) as ServerError;
+
+            networkError.statusCode = response.status;
+
+            throw networkError;
           }
 
           if (!response.body) {
@@ -66,7 +77,6 @@ export class StreamingRestLink extends ApolloLink {
 
           const reader = response.body.getReader();
           const decoder = new TextDecoder();
-          let accumulatedData = '';
 
           let isStreaming = true;
           while (isStreaming) {
@@ -79,19 +89,9 @@ export class StreamingRestLink extends ApolloLink {
             }
 
             const decodedChunk = decoder.decode(value, { stream: true });
-            accumulatedData += decodedChunk;
 
             if (isDefined(onChunk) && typeof onChunk === 'function') {
-              onChunk(accumulatedData);
-            }
-
-            try {
-              const parsedData = JSON.parse(decodedChunk);
-              observer.next({ data: parsedData });
-            } catch {
-              observer.next({
-                data: { streamingData: decodedChunk },
-              });
+              onChunk(decodedChunk);
             }
           }
         })