EstadoAlarmas, EstadoGrabacion and EstadoRadio defaulted `esPremium` to
`() => true`, so any construction site that forgot to wire entitlement
compiled fine and silently ran ungated — failing OPEN to premium and
disabling the paywall with no test able to catch it.
The parameter is now required with no default. Production wiring in
app.dart was already correct and is unchanged; the 184 pre-existing test
call sites now pass `() => true` explicitly, which is exactly the old
implicit default, so every assertion is untouched.
EstadoRadio has no gate of its own but constructs EstadoGrabacion, so it
inherits the same contract.
The one test that existed to pin the old default is renamed to describe
what it still covers (the premium path through iniciar() with no
duracion); its assertions are unchanged.
Tier 4 visual fidelity, audit 7.5 (t4 line 334): the prototype stacks
alarm cards with a 10px gap; the build used 12. Each gap is now keyed
per alarm id so a guard test can pin the exact value between two known
cards.