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/scripts/check-model-data.ts

@@ -0,0 +1,16 @@
+#!/usr/bin/env node
+
+import { dirname, join } from "node:path";
+import { fileURLToPath } from "node:url";
+import { validateGeneratedModelData } from "./model-data.ts";
+
+const packageRoot = join(dirname(fileURLToPath(import.meta.url)), "..");
+
+try {
+	validateGeneratedModelData(packageRoot);
+	console.log("Generated model data is valid.");
+} catch (error) {
+	console.error(error instanceof Error ? error.message : String(error));
+	console.error("\nModel data is missing or stale. Run `npm run hydrate:model-data` from the repository root.");
+	process.exitCode = 1;
+}