feat: add Night Shift layer (boot intro, ops strip, headlight, chapter numerals, film grain)

tests/unit/operations.test.ts

@@ -0,0 +1,21 @@
+import { describe, expect, it } from 'vitest';
+import { bucharestClock, uptimeSince } from '@/lib/operations';
+
+describe('uptimeSince', () => {
+  const start = new Date('2025-08-01T00:00:00Z');
+  it('is zero at the start', () => {
+    expect(uptimeSince(start, start)).toEqual({ months: 0, days: 0 });
+  });
+  it('counts whole months and remaining days', () => {
+    expect(uptimeSince(start, new Date('2026-10-10T00:00:00Z'))).toEqual({ months: 14, days: 9 });
+  });
+  it('clamps to zero before the start', () => {
+    expect(uptimeSince(start, new Date('2025-01-01T00:00:00Z'))).toEqual({ months: 0, days: 0 });
+  });
+});
+
+describe('bucharestClock', () => {
+  it('formats HH:MM in Europe/Bucharest', () => {
+    expect(bucharestClock(new Date('2026-01-15T10:05:00Z'))).toBe('12:05');
+  });
+});