chore(vendor): import pi 0.85.1

Imported as a linear vendor commit so forge rebases do not replay the upstream root tree.

git-subtree-dir: third_party/pi

git-subtree-split: d981de1229ef899957bbe968bc8dcda02a21f477

third_party/pi/packages/ai/src/images.ts

@@ -0,0 +1,21 @@
+import "./providers/images/register-builtins.ts";
+
+import { getImagesApiProvider } from "./images-api-registry.ts";
+import type { AssistantImages, ImagesApi, ImagesContext, ImagesModel, ProviderImagesOptions } from "./types.ts";
+
+function resolveImagesApiProvider(api: ImagesApi) {
+	const provider = getImagesApiProvider(api);
+	if (!provider) {
+		throw new Error(`No API provider registered for api: ${api}`);
+	}
+	return provider;
+}
+
+export async function generateImages<TApi extends ImagesApi>(
+	model: ImagesModel<TApi>,
+	context: ImagesContext,
+	options?: ProviderImagesOptions,
+): Promise<AssistantImages> {
+	const provider = resolveImagesApiProvider(model.api);
+	return provider.generateImages(model, context, options);
+}