feat: extend ShellDocsOptions with logo properties and methods for enhanced branding support

Author: Shewart

src/ShellDocs.Components/ShellDocsOptions.cs

@@ -10,6 +10,13 @@ public class ShellDocsOptions
     public string SiteName { get; set; } = "";
     public string? SiteTagline { get; set; }
     public string? GitHubRepo { get; set; }
+
+    public string? LogoLight { get; set; }
+    public string? LogoDark { get; set; }
+    public string? LogoAlt { get; set; }
+    public double LogoHeight { get; set; } = 1.375;
+    // Rendered as MarkupString — must be trusted content the consumer authored, not user input.
+    public string? LogoSvg { get; set; }
     public ShellDocsTheme Theme { get; set; } = ShellDocsTheme.Shadcn;
     public DocsLayoutVariant LayoutVariant { get; set; } = DocsLayoutVariant.TopNav;
 
@@ -117,6 +124,22 @@ public ShellDocsOptions AddPackage(string id, string title, string description,
         return this;
     }
 
+    public ShellDocsOptions SetLogo(string url, string? alt = null)
+    {
+        LogoLight = url;
+        LogoDark = url;
+        if (alt is not null) LogoAlt = alt;
+        return this;
+    }
+
+    public ShellDocsOptions SetLogo(string lightUrl, string darkUrl, string? alt = null)
+    {
+        LogoLight = lightUrl;
+        LogoDark = darkUrl;
+        if (alt is not null) LogoAlt = alt;
+        return this;
+    }
+
     internal TypeRegistry BuildTypeRegistry()
     {
         var registry = new TypeRegistry();