feat: create Bruno requests for library system API

- Add library management requests (CRUD operations)
- Create media items API requests for library content
- Implement library visibility controls
- Add user library access management
- Update deprecated ebook folder endpoints with migration guide
- Include comprehensive documentation and test cases
- Replace collection.bru with proper dashboard request

Complete Bruno collection supporting new multi-library architecture

bruno/admin/Get Admin Library.bru

@@ -1,11 +1,21 @@
 meta {
-  name: Get Admin Library
-  type: http
+  name: Get Admin Library Page
+  type: http,
   seq: 5
 }
 
 get {
-  url: {{base_url}}/admin/library
-  body: none
-  auth: bearer
+  url: "/admin/library"
+  headers: {
+    Authorization: "Bearer {{ _.token }}"
+  }
 }
+
+tests: {
+  test_admin_library_page_success: {
+    status: 200,
+    headers: {
+      "content-type": "text/html; charset=UTF-8"
+    }
+  }
+}