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/collection.bru

@@ -0,0 +1,21 @@
+meta {
+  name: Get Dashboard Page
+  type: http,
+  seq: 1
+}
+
+get {
+  url: "/dashboard"
+  headers: {
+    Authorization: "Bearer {{ _.token }}"
+  }
+}
+
+tests: {
+  test_dashboard_success: {
+    status: 200,
+    headers: {
+      "content-type": "text/html; charset=UTF-8"
+    }
+  }
+}