aa661526

By: Michael Lynch <git@mtlynch.io>

Fix time_test.go per AGENTS.md conventions

- Use a hardcoded fixed time instead of time.Now() in tests.
- Inject now as an explicit time.Time parameter to RelativeTime so
  production code is testable without relying on the wall clock.
- Rename label/expected fields to explanation/relativeTimeExpected.
- Switch to the if got, want pattern for assertions.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>