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/devices/Delete Device.bru

@@ -7,9 +7,39 @@ meta {
 delete {
   url: {{baseUrl}}/api/devices/{{deviceId}}
   body: none
-  auth: bearer
+  auth: inherit
 }
 
-headers: {
+headers {
   Authorization: Bearer {{token}}
 }
+
+settings {
+  encodeUrl: true
+  timeout: 0
+}
+
+docs {
+  ## Delete Device
+
+  Deletes a device and unregisters it from the user's account.
+
+  **Method:** DELETE
+
+  **Endpoint:** /api/devices/{deviceId}
+
+  **Authentication:** Bearer token
+
+  **Path Parameters:**
+  - `deviceId` (string): Device UUID
+
+  **Response:** 204 No Content on success
+
+  **Status Codes:**
+  - 204: Success - device deleted
+  - 401: Unauthorized
+  - 404: Device not found
+  - 500: Internal server error
+
+  **Note:** This action cannot be undone. All device data and sync history will be removed.
+}