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/sync-kobo/Bulk Link Books.bru

@@ -1,34 +1,70 @@
-{
-  "meta": {
-    "name": "Bulk Link Unlinked Books",
-    "type": "http"
-  },
-  "req": {
-    "url": "{{baseUrl}}/sync/bulk-link-books",
-    "method": "POST",
-    "header": [
+meta {
+  name: Bulk Link Unlinked Books
+  type: http
+  seq: 1
+}
+
+post {
+  url: {{baseUrl}}/sync/bulk-link-books
+  body: json
+  auth: inherit
+}
+
+headers {
+  Content-Type: application/json
+  Authorization: Bearer {{authToken}}
+}
+
+body:json {
+  {
+    "links": [
       {
-        "key": "Content-Type",
-        "value": "application/json"
+        "unlinked_book_id": "{{unlinkedBookId1}}",
+        "media_item_id": "{{mediaItemId1}}",
+        "confidence_score": 1.0
       },
       {
-        "key": "Authorization",
-        "value": "Bearer {{authToken}}"
+        "unlinked_book_id": "{{unlinkedBookId2}}",
+        "media_item_id": "{{mediaItemId2}}",
+        "confidence_score": 0.9
       }
-    ],
-    "body": {
-      "links": [
-        {
-          "unlinked_book_id": "{{unlinkedBookId1}}",
-          "media_item_id": "{{mediaItemId1}}",
-          "confidence_score": 1.0
-        },
-        {
-          "unlinked_book_id": "{{unlinkedBookId2}}",
-          "media_item_id": "{{mediaItemId2}}",
-          "confidence_score": 0.9
-        }
-      ]
-    }
+    ]
   }
 }
+
+settings {
+  encodeUrl: true
+  timeout: 0
+}
+
+docs {
+  ## Bulk Link Unlinked Books
+
+  Links multiple unlinked books to media items in a single request.
+
+  **Method:** POST
+
+  **Endpoint:** /sync/bulk-link-books
+
+  **Authentication:** Bearer token
+
+  **Request Body:**
+  - `links` (array): Array of link objects
+    - `unlinked_book_id` (string): Unlinked book UUID
+    - `media_item_id` (string): Media item UUID to link to
+    - `confidence_score` (number): Match confidence (0-1)
+
+  **Response:**
+  - `results` (array): Results for each link attempt
+  - `total` (number): Total number of links processed
+  - `success` (number): Number of successful links
+  - `failed` (number): Number of failed links
+
+  **Status Codes:**
+  - 200: Success
+  - 400: Invalid request data
+  - 401: Unauthorized
+  - 500: Internal server error
+
+  **Note:** Use this endpoint after reviewing suggestions from the Get Unlinked Book Suggestions endpoint.
+}