Refactor API response structure to use 'body' instead of 'data' for consistency across all endpoints. Update stub responses and documentation accordingly.

stubs/api/README.md

@@ -50,18 +50,19 @@ stubs/api/
 ### Успешный ответ
 ```json
 {
-  "error": null,
-  "data": <данные>
+  "success": true,
+  "body": <данные>
 }
 ```
 
 ### Ошибка
 ```json
 {
+  "success": false,
+  "body": null,
   "error": {
     "message": "Описание ошибки"
-  },
-  "data": null
+  }
 }
 ```
 

stubs/api/index.js

@@ -11,14 +11,15 @@ const loadJSON = (filename) => {
   return JSON.parse(data);
 };
 
-const respond = (res, data) => {
-  res.json({ error: null, data });
+const respond = (res, body) => {
+  res.json({ success: true, body });
 };
 
 const respondError = (res, message, statusCode = 400) => {
   res.status(statusCode).json({ 
-    error: { message }, 
-    data: null 
+    success: false,
+    body: null,
+    error: { message }
   });
 };