test(cli): regression test for pi-migration.getPiDefaultModelAndProvider export

Asserts that getPiDefaultModelAndProvider and migratePiCredentials remain
callable top-level exports from src/pi-migration.ts. If either is ever
renamed or unexported, this test fails before the root `tsc` build breaks
every CI job on main — the same class of regression introduced by
110c01b8c.

src/tests/pi-migration-exports.test.ts

@@ -0,0 +1,23 @@
+// GSD-2 — Regression test for pi-migration.ts public exports consumed by cli.ts
+//
+// Guards against the TS2304 regression introduced by 080c6ac1e where
+// src/cli.ts called `getPiDefaultModelAndProvider()` without importing it.
+// If the symbol is ever renamed or unexported, this test fails before the
+// root `tsc` build breaks every CI job on main.
+
+import { test } from "node:test";
+import assert from "node:assert/strict";
+
+import * as piMigration from "../pi-migration.js";
+
+test("pi-migration exports getPiDefaultModelAndProvider for cli.ts fallback-model resolution", () => {
+	assert.equal(
+		typeof piMigration.getPiDefaultModelAndProvider,
+		"function",
+		"cli.ts validateConfiguredModel relies on this export to pick a fallback model",
+	);
+});
+
+test("pi-migration exports migratePiCredentials for cli.ts startup migration", () => {
+	assert.equal(typeof piMigration.migratePiCredentials, "function");
+});