feat(11-04): add UpdateProfileAsync to ProfileService and ImportLogoFromBytesAsync to BrandingService

- ProfileService.UpdateProfileAsync: replaces profile by name and persists the change
- IBrandingService: add ImportLogoFromBytesAsync to interface contract
- BrandingService.ImportLogoFromBytesAsync: validates magic bytes, compresses if > 512KB, returns LogoData
- BrandingService.ImportLogoAsync: refactored to delegate to ImportLogoFromBytesAsync
- ProfileServiceTests: 2 new tests (UpdateProfileAsync happy path + KeyNotFoundException)
- BrandingServiceTests: 2 new tests (ImportLogoFromBytesAsync valid PNG + invalid bytes)
- Tests.csproj: suppress NU1701 for pre-existing LiveCharts2/OpenTK transitive warnings

SharepointToolbox/Services/BrandingService.cs

@@ -30,7 +30,15 @@ public class BrandingService : IBrandingService
     public async Task<LogoData> ImportLogoAsync(string filePath)
     {
         var bytes = await File.ReadAllBytesAsync(filePath);
+        return await ImportLogoFromBytesAsync(bytes);
+    }
 
+    /// <summary>
+    /// Validates raw bytes as PNG or JPEG via magic bytes, auto-compresses if over 512 KB,
+    /// and returns a LogoData record. Used when bytes are obtained from a stream (e.g. Entra branding API).
+    /// </summary>
+    public Task<LogoData> ImportLogoFromBytesAsync(byte[] bytes)
+    {
         var mimeType = DetectMimeType(bytes);
 
         if (bytes.Length > MaxSizeBytes)
@@ -38,11 +46,11 @@ public class BrandingService : IBrandingService
             bytes = CompressToLimit(bytes, mimeType, MaxSizeBytes);
         }
 
-        return new LogoData
+        return Task.FromResult(new LogoData
         {
             Base64 = Convert.ToBase64String(bytes),
             MimeType = mimeType
-        };
+        });
     }
 
     public async Task SaveMspLogoAsync(LogoData logo)