Refactor code structure for improved readability and maintainability; optimize performance in key functions.

src/Cli/StellaOps.Cli/Services/IOciRegistryClient.cs

@@ -0,0 +1,23 @@
+using StellaOps.Cli.Services.Models;
+
+namespace StellaOps.Cli.Services;
+
+public interface IOciRegistryClient
+{
+    Task<string> ResolveDigestAsync(OciImageReference reference, CancellationToken cancellationToken = default);
+
+    Task<OciReferrersResponse> ListReferrersAsync(
+        OciImageReference reference,
+        string digest,
+        CancellationToken cancellationToken = default);
+
+    Task<OciManifest> GetManifestAsync(
+        OciImageReference reference,
+        string digest,
+        CancellationToken cancellationToken = default);
+
+    Task<byte[]> GetBlobAsync(
+        OciImageReference reference,
+        string digest,
+        CancellationToken cancellationToken = default);
+}