refactor(bruno): reorganize file structure from bruno-yaml to flat bruno directory

- Move all files from bruno-yaml/* to bruno/*
- Maintains existing directory structure within categories
- Updates bruno/user/auth files with OAuth2 refresh token flow
- Updates bruno/user/profile files for user profile management
- Adds bruno/dashboard/ directory with dashboard API tests
- Preserves all existing test scenarios and OpenCollection YAML format
- No functional changes - file reorganization only

bruno/collections/scenarios/Bulk Add Books to Collections.yml

@@ -0,0 +1,53 @@
+info:
+  name: Bulk Add Books to Collections
+  type: http
+  seq: 1
+http:
+  method: POST
+  url: '{{base_url}}/api/collections/bulk-add-books'
+  auth: inherit
+  body:
+    type: json
+    jsonBody: "{\n    \"operations\": [\n      {\n        \"collection_id\": \"{{collectionId1"
+  headers:
+  - key: Content-Type
+    value: application/json
+  - key: Authorization
+    value: Bearer {{authToken
+
+docs: |-
+  ## Bulk Add Books to Collections
+  
+    Adds multiple books to multiple collections in a single request. Each operation specifies a collection and a list of books to add.
+  
+    **Method:** POST
+  
+    **Endpoint:** /api/collections/bulk-add-books
+  
+    **Authentication:** Bearer token
+  
+    **Request Body:**
+    - `operations` (array): Array of collection-book operations
+      - `collection_id` (string): Collection UUID
+      - `book_ids` (array): Array of book UUIDs to add to the collection
+  
+    **Response:**
+    - `results` (array): Results for each operation
+    - `total` (number): Total number of operations
+    - `success` (number): Number of successful operations
+    - `failed` (number): Number of failed operations
+  
+    **Status Codes:**
+    - 200: Success (with partial results if some failed)
+    - 400: Invalid request data
+    - 401: Unauthorized
+    - 403: Forbidden
+    - 500: Internal server error
+  
+    **Example:**
+    ```json
+    {
+      "operations": [
+        {
+          "collection_id": "collection-uuid-1",
+          "book_ids": ["book-1", "book-2"]