Add the model matching engine and make capabilities a flags enum

app/MindWork AI Studio/Models/TokenizerKind.cs

@@ -0,0 +1,38 @@
+namespace AIStudio.Models;
+
+/// <summary>
+/// What sort of tokenizer a model uses, and therefore how its name would have to be resolved.
+/// </summary>
+/// <remarks>
+/// A bare name would be a lie. The runtime loads Hugging Face tokenizer.json files, OpenAI names
+/// tiktoken encodings such as o200k_base, and Anthropic and Google publish no tokenizer at all but
+/// offer an API which counts for you. Without the kind next to the name, somebody would eventually
+/// try to fetch "o200k_base" from a model hub.
+/// </remarks>
+public enum TokenizerKind
+{
+    /// <summary>
+    /// We have no statement about this model's tokenizer, so the built-in default one is used.
+    /// </summary>
+    UNKNOWN,
+
+    /// <summary>
+    /// A repository on the Hugging Face hub which ships a tokenizer.json.
+    /// </summary>
+    HUGGING_FACE,
+
+    /// <summary>
+    /// A tiktoken encoding, named the way OpenAI names it.
+    /// </summary>
+    TIKTOKEN,
+
+    /// <summary>
+    /// The vendor counts tokens through an API of its own instead of publishing a tokenizer.
+    /// </summary>
+    PROVIDER_API,
+
+    /// <summary>
+    /// The model has no tokenizer to speak of, such as an image or audio model.
+    /// </summary>
+    NONE,
+}