test(metadata-protocol): add self-contained public-surface smoke

`@objectstack/metadata-protocol` had a `test` script but no test files, so
`vitest run` exited non-zero and failed CI's Test Core (`turbo run test`).
Adds a smoke that imports the package and asserts its public exports + pure
helpers without needing a data engine (protocol behavior is covered e2e by the
objectql suite). Full `turbo run test` now green (126/126 tasks).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: os-zhuang

packages/metadata-protocol/src/index.test.ts

@@ -0,0 +1,47 @@
+// Copyright (c) 2025 ObjectStack. Licensed under the Apache-2.0 license.
+//
+// Self-contained smoke for @objectstack/metadata-protocol: the package must
+// import cleanly and expose its public surface without needing a data engine.
+// (Protocol behavior is exercised end-to-end by the @objectstack/objectql suite,
+// which injects a real engine.)
+
+import { describe, it, expect } from 'vitest';
+import {
+  ObjectStackProtocolImplementation,
+  ConcurrentUpdateError,
+  normalizeViewMetadata,
+  SysMetadataRepository,
+  resetEnvWritableMetadataTypes,
+  computeMetadataDiagnostics,
+  computeViewReferenceDiagnostics,
+  decorateMetadataItem,
+  SeedLoaderService,
+  runBuildProbes,
+} from './index.js';
+
+describe('@objectstack/metadata-protocol public surface', () => {
+  it('exposes the protocol, repository, seed-loader and probe entry points', () => {
+    expect(typeof ObjectStackProtocolImplementation).toBe('function');
+    expect(typeof SysMetadataRepository).toBe('function');
+    expect(typeof SeedLoaderService).toBe('function');
+    expect(typeof runBuildProbes).toBe('function');
+    expect(ConcurrentUpdateError.prototype).toBeInstanceOf(Error);
+  });
+
+  it('exposes pure metadata helpers', () => {
+    expect(typeof normalizeViewMetadata).toBe('function');
+    expect(typeof computeMetadataDiagnostics).toBe('function');
+    expect(typeof computeViewReferenceDiagnostics).toBe('function');
+    expect(typeof decorateMetadataItem).toBe('function');
+    expect(typeof resetEnvWritableMetadataTypes).toBe('function');
+  });
+
+  it('normalizeViewMetadata passes a non-view item through without throwing', () => {
+    const item = { name: 'acct', label: 'Account' };
+    expect(() => normalizeViewMetadata('object', item, 'acct')).not.toThrow();
+  });
+
+  it('resetEnvWritableMetadataTypes is callable (state reset, no engine needed)', () => {
+    expect(() => resetEnvWritableMetadataTypes()).not.toThrow();
+  });
+});