Port the OpenAI families and add the model registry

app/MindWork AI Studio/Models/OpenAI/Gpt4Family.cs

@@ -0,0 +1,31 @@
+using static AIStudio.Provider.Capability;
+
+namespace AIStudio.Models.OpenAI;
+
+/// <summary>
+/// GPT-4 and GPT-4 Turbo.
+/// </summary>
+/// <remarks>
+/// GPT-4o is not one of these, which the name hides and the matching does not: a rule bound to the
+/// start of a name only answers where a name part ends, and in "gpt-4o" the part goes on. The
+/// previous rules had to say that twice, once as an exact comparison and once as a prefix.
+/// </remarks>
+public sealed class Gpt4Family : ModelFamily
+{
+    /// <inheritdoc />
+    public override ModelVendor Vendor => ModelVendor.OPEN_AI;
+
+    /// <inheritdoc />
+    public override ModelSource Source => new("https://platform.openai.com/docs/models", new DateOnly(2026, 9, 11), "Ported unchanged from the rules in ProviderExtensions.OpenAI.cs: GPT-4 is text only, Turbo adds images and tool calling.");
+
+    /// <inheritdoc />
+    protected override void Declare(ModelFamilyBuilder builder)
+    {
+        builder.Rule("gpt-4").AsPrefix()
+            .Capabilities(TEXT_INPUT | TEXT_OUTPUT)
+            .Apis(RESPONSES_API);
+
+        builder.Rule("gpt-4-turbo").AsPrefix().Inherits()
+            .Capabilities(MULTIPLE_IMAGE_INPUT | FUNCTION_CALLING);
+    }
+}