- CalendarShell now captures maybeRedirectToLogin() return value in meQuery.isError effect
- When the one-shot guard is exhausted (returns false), arm loginRedirectExhausted state
- Render AuthSplash state=dead-end (tap-to-retry) when guard is exhausted, not indefinite redirecting spinner
- Reset loginRedirectExhausted on successful auth (meQuery.isSuccess) for session recovery
- Add sessionStorage.clear() to beforeEach so CalendarShell tests are isolated
- RED test committed in prior commit (36ef7a0)