Refactor API classes to use BaseCrudApi for CRUD ops

Introduce BaseCrudApi to encapsulate common CRUD logic for API resource classes. Refactor CommonApi, EndpointAuthApi, EndpointParamsApi, EndpointsApi, ProfileApi, RecActionApi, and ResultApi to inherit from BaseCrudApi, removing duplicated CRUD methods and constructors. This centralizes CRUD operations, reduces code duplication, and improves maintainability.

src/ReC.Client/Api/BaseCrudApi.cs

@@ -0,0 +1,71 @@
+using System;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace ReC.Client.Api
+{
+    /// <summary>
+    /// Provides shared CRUD operations for API resources.
+    /// </summary>
+    public abstract class BaseCrudApi
+    {
+        /// <summary>
+        /// The HTTP client used to send requests.
+        /// </summary>
+        protected readonly HttpClient Http;
+
+        /// <summary>
+        /// The base resource path for the API endpoint.
+        /// </summary>
+        protected readonly string ResourcePath;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="BaseCrudApi"/> class.
+        /// </summary>
+        /// <param name="http">The HTTP client used for requests.</param>
+        /// <param name="resourcePath">The base resource path for the API endpoint.</param>
+        protected BaseCrudApi(HttpClient http, string resourcePath)
+        {
+            Http = http ?? throw new ArgumentNullException(nameof(http));
+            ResourcePath = resourcePath ?? throw new ArgumentNullException(nameof(resourcePath));
+        }
+
+        /// <summary>
+        /// Creates a resource.
+        /// </summary>
+        /// <typeparam name="T">The payload type.</typeparam>
+        /// <param name="payload">The payload to send.</param>
+        /// <param name="cancel">A token to cancel the operation.</param>
+        /// <returns>The HTTP response message.</returns>
+        public Task<HttpResponseMessage> CreateAsync<T>(T payload, CancellationToken cancel = default)
+            => Http.PostAsync(ResourcePath, ReCClientHelpers.ToJsonContent(payload), cancel);
+
+        /// <summary>
+        /// Updates a resource by identifier.
+        /// </summary>
+        /// <typeparam name="T">The payload type.</typeparam>
+        /// <param name="id">The resource identifier.</param>
+        /// <param name="payload">The payload to send.</param>
+        /// <param name="cancel">A token to cancel the operation.</param>
+        /// <returns>The HTTP response message.</returns>
+        public Task<HttpResponseMessage> UpdateAsync<T>(long id, T payload, CancellationToken cancel = default)
+            => Http.PutAsync($"{ResourcePath}/{id}", ReCClientHelpers.ToJsonContent(payload), cancel);
+
+        /// <summary>
+        /// Deletes resources with identifiers supplied in the payload.
+        /// </summary>
+        /// <typeparam name="T">The payload type containing identifiers.</typeparam>
+        /// <param name="payload">The payload to send.</param>
+        /// <param name="cancel">A token to cancel the operation.</param>
+        /// <returns>The HTTP response message.</returns>
+        public Task<HttpResponseMessage> DeleteAsync<T>(T payload, CancellationToken cancel = default)
+        {
+            var request = new HttpRequestMessage(HttpMethod.Delete, ResourcePath)
+            {
+                Content = ReCClientHelpers.ToJsonContent(payload)
+            };
+            return Http.SendAsync(request, cancel);
+        }
+    }
+}