Tighten layer graph tests and document npm test typecheck.

Content and People/Schedule/Ai now fail the same way if they grow a game-layer edge the projects.md graph forbids; README matches the tsc-then-vitest script from phase 57.

src/HSchool.Client/scripts/npm-test.test.ts

@@ -33,6 +33,10 @@ describe('npm test script', () => {
   it('does not depend on the hschool-client file: loop', () => {
     expect(pkg.dependencies?.['hschool-client']).toBeUndefined();
   });
+
+  it('keeps build as typecheck then vite, without the file: loop', () => {
+    expect(pkg.scripts.build).toBe('tsc -b && vite build');
+  });
 });
 
 describe('duplicate dictionary keys', () => {