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/initialization.bru

@@ -1,5 +1,5 @@
 meta {
-  name: "Kobo Initialization - Enhanced with ContentId Mapping"
+  name: Kobo Initialization
   type: http
   seq: 1
 }
@@ -7,15 +7,49 @@ meta {
 get {
   url: {{base_url}}/api/v1/kobo/initialization
   body: none
-  auth: {
-    type: bearer
-    bearer: {{device_token}}
-  }
+  auth: inherit
 }
 
-assert {
-  response.status == 200
-  response.body.ContentId exists()
-  response.body.Categories exists()
-  response.body.BookhoardUUID exists()
+headers {
+  Authorization: Bearer {{device_token}}
+  Content-Type: application/json
+}
+
+script:post-response {
+  function onResponse(res) {
+    if (res.getStatus() === 200) {
+      const body = res.getBody();
+      tests('Has ContentId', body.ContentId !== undefined);
+      tests('Has Categories', body.Categories !== undefined);
+      tests('Has BookhoardUUID', body.BookhoardUUID !== undefined);
+    }
+  }
+  onResponse(res);
+}
+
+settings {
+  encodeUrl: true
+  timeout: 0
+}
+
+docs {
+  ## Kobo Initialization
+
+  Initializes Kobo device sync, returning device resources and account information.
+
+  **Method:** GET
+
+  **Endpoint:** /api/v1/kobo/initialization
+
+  **Authentication:** Bearer token (device token)
+
+  **Response:**
+  - `ContentId` (string): Device content ID
+  - `Categories` (array): Available categories/collections
+  - `BookhoardUUID` (string): Bookhoard instance UUID
+
+  **Status Codes:**
+  - 200: Success
+  - 401: Unauthorized
+  - 500: Internal server error
 }