Port the OpenAI families and add the model registry

app/MindWork AI Studio/Models/OpenAI/Gpt4oFamily.cs

@@ -0,0 +1,43 @@
+using static AIStudio.Provider.Capability;
+
+namespace AIStudio.Models.OpenAI;
+
+/// <summary>
+/// GPT-4o, including its mini and its audio preview.
+/// </summary>
+/// <remarks>
+/// The previous rules never named this family. Its models reached the last line of the OpenAI
+/// function, the one which answers for everything nobody wrote a rule for, and that line happened
+/// to describe GPT-4o exactly. Writing it down changes no answer and takes the family out of the
+/// fallback, where a wrong answer looks like no answer.
+/// </remarks>
+public sealed class Gpt4oFamily : ModelFamily
+{
+    /// <inheritdoc />
+    public override ModelVendor Vendor => ModelVendor.OPEN_AI;
+
+    /// <inheritdoc />
+    public override ModelSource Source => new("https://platform.openai.com/docs/models/gpt-4o", new DateOnly(2026, 9, 11), "The answer the previous rules gave these models through their fallback: images, tool calling, and web search on the Responses API.");
+
+    /// <inheritdoc />
+    protected override void Declare(ModelFamilyBuilder builder)
+    {
+        builder.Rule("gpt-4o").AsPrefix()
+            .Capabilities(TEXT_INPUT | MULTIPLE_IMAGE_INPUT | TEXT_OUTPUT | FUNCTION_CALLING | WEB_SEARCH)
+            .Apis(RESPONSES_API);
+
+        //
+        // The search previews are the same generation and almost nothing like it: they search the
+        // web and do nothing else, no images and no tools, and they answer only through the chat
+        // completion API. Stated in full rather than inherited, because there is barely anything of
+        // the family left in them.
+        //
+        builder.Rule("gpt-4o-search-preview").AsExact()
+            .Capabilities(TEXT_INPUT | TEXT_OUTPUT | WEB_SEARCH)
+            .Apis(CHAT_COMPLETION_API);
+
+        builder.Rule("gpt-4o-mini-search-preview").AsExact()
+            .Capabilities(TEXT_INPUT | TEXT_OUTPUT | WEB_SEARCH)
+            .Apis(CHAT_COMPLETION_API);
+    }
+}