feat: add comprehensive Bruno API tests for annotations

- Add complete Bruno collection for notes API (5 endpoints)
- Add complete Bruno collection for highlights API (5 endpoints)
- Include detailed request/response documentation
- Add proper validation examples and error cases
- Support both media-items and ebook endpoint testing
- Add environment variable support for dynamic IDs

bruno/notes/Create Media Note.bru

@@ -0,0 +1,53 @@
+meta {
+  name: Create Media Note
+  type: http
+  seq: 2
+}
+
+post {
+  url: {{base_url}}/api/media-items/{{media_item_id}}/notes
+  body: json
+  auth: inherit
+}
+
+body:json {
+  {
+    "content": "This is a test note about this media item.",
+    "position": "page:45"
+  }
+}
+
+script:post-response {
+  onResponse(res);
+}
+
+settings {
+  encodeUrl: true
+  timeout: 0
+}
+
+docs {
+  ## Create Media Note
+  
+  Creates a new note for a specific media item.
+  
+  **Method:** POST
+  
+  **Endpoint:** /api/media-items/:id/notes
+  
+  **Path Parameters:**
+  - `id` (string): Media item ID
+  
+  **Request Body:**
+  - `content` (string): Note content (required, 1-10000 chars)
+  - `position` (string): Optional position reference (max 100 chars)
+  
+  **Response:**
+  - Note object with all fields including generated ID and timestamps
+  
+  **Status Codes:**
+  - 201: Created
+  - 400: Invalid request
+  - 401: Unauthorized
+  - 404: Media item not found
+}