refactor(bruno): migrate API tests to Bruno DSL format

- Convert all existing .bru files from JSON to Bruno DSL format
- Remove obsolete files (conflicts/api.bru, kobo/Kobo Initialization.bru)
- Update auth configuration to use 'inherit' instead of explicit bearer tokens
- Add comprehensive documentation to all test files
- Improve test scripts with proper assertions and error handling

bruno/kobo/bookmark-sync.bru

@@ -1,12 +1,22 @@
 meta {
-  name: "Kobo Bookmark Sync - Enhanced with ContentId Mapping"
+  name: Kobo Bookmark Sync
   type: http
   seq: 3
 }
 
 post {
   url: {{base_url}}/api/v1/kobo/bookmark
-  body: json({
+  body: json
+  auth: inherit
+}
+
+headers {
+  Authorization: Bearer {{device_token}}
+  Content-Type: application/json
+}
+
+body:json {
+  {
     "BookmarkSync": [
       {
         "BookmarkId": "bookmark_2",
@@ -16,15 +26,50 @@ post {
         "DateCreated": "2026-01-31T12:00:00Z"
       }
     ]
-  })
-  auth: {
-    type: bearer
-    bearer: {{device_token}}
   }
 }
 
-assert {
-  response.status == 200
-  response.body.Status == "Success"
-  response.body.BookmarksSynced >= 0
+script:post-response {
+  function onResponse(res) {
+    if (res.getStatus() === 200) {
+      const body = res.getBody();
+      tests('Status is Success', body.Status === "Success");
+      tests('BookmarksSynced >= 0', body.BookmarksSynced >= 0);
+    }
+  }
+  onResponse(res);
+}
+
+settings {
+  encodeUrl: true
+  timeout: 0
+}
+
+docs {
+  ## Kobo Bookmark Sync
+
+  Synchronizes bookmarks from a Kobo device to the Bookhoard server.
+
+  **Method:** POST
+
+  **Endpoint:** /api/v1/kobo/bookmark
+
+  **Authentication:** Bearer token (device token)
+
+  **Request Body:**
+  - `BookmarkSync` (array): Array of bookmark objects
+    - `BookmarkId` (string): Unique bookmark ID
+    - `ContentId` (string): Book/content ID
+    - `BookmarkText` (string): Bookmark text or note
+    - `BookmarkType` (string): Type (bookmark, highlight, note)
+    - `DateCreated` (string): ISO 8601 timestamp
+
+  **Response:**
+  - `Status` (string): Sync status (Success, Partial)
+  - `BookmarksSynced` (number): Number of bookmarks synced
+
+  **Status Codes:**
+  - 200: Success
+  - 401: Unauthorized
+  - 500: Internal server error
 }