fix(credential-groups): pin the clock in the enrollment tests - #6812

Summary

apps/sim/lib/credential-groups/enrollments.test.ts had a time bomb that has now gone off. It blocks CI on every branch, not just this one.

ENROLLMENT.invitationExpiresAt was hardcoded to 2026-08-18T12:00:00.000Z, and completeCredentialGroupEnrollment compares it against the wall clock. Before that instant the invitation was valid and the suite passed; after it, the invitation is expired, the function returns null, and two tests fail.

The evidence is a single unchanged commit running twice:

Same SHA, same base, no code change between them — only the clock moved past 12:00Z.

Confirmed locally: on clean origin/staging the two tests fail deterministically; re-dating the fixture to 2027 makes all 11 pass.

Fix

Pin the clock to a point inside the invitation window rather than re-dating the fixture:

const NOW = new Date('2026-08-11T12:10:00.000Z')
beforeEach(() => {
  vi.useFakeTimers({ shouldAdvanceTime: true })
  vi.setSystemTime(NOW)
})
afterEach(() => { vi.useRealTimers() })

Every existing date literal keeps its meaning, and the suite stops depending on when it runs. Bumping the date to a later instant would only re-arm the same failure.

Type of Change

• Bug fix (broken CI)

Testing

lib/credential-groups — 63 tests across 13 files pass. type-check clean, lint clean. Verified the cause by moving the fixture date forward and back.

Checklist

• Code follows project style guidelines
• Self-reviewed my changes
• Tests added/updated and passing
• No new warnings introduced
• I confirm that I have read and agree to the terms outlined in the Contributor License Agreement (CLA)