Reads

This operation does not mutate — said out loud, because silence must not be the way to say it. The acta first wrote «the absence of {@see Mutates} means it does not mutate». Building it showed that to be the permissive default GOV-13 forbids, arrived at from silence: an author who FORGETS the declaration would ship `mutating: false` on an operation that writes, and every consumer would believe it. So absence is an error, and this attribute is how a read declares itself. With nothing declared it IS {@see EffectProfile::readOnly()} — the profile this package already ships as the canonical read, down to the `nothing-to-roll-back` contract. That reuse is deliberate: a second opinion about what «read-only» means is exactly the second source of truth the whole package refuses. Two axes stay open, because a read is not automatically harmless: `externality` (reading a customer's record and mailing it to a third party is, on the mutation axis, still a read) and `authority` (whose credentials it spends). There is no `subject` here on purpose — {@see EffectProfile} refuses `Mutation::None` beside a subject, since a change to nothing is a change of nothing, and a knob whose every value is refused is worse than no knob.

public function __construct(Milpa\Command\Effect\Externality $externality = Milpa\Command\Effect\Externality::None, Milpa\Command\Effect\Authority $authority = Milpa\Command\Effect\Authority::Read, array $escalatesOn = []):

Parameters

public function profile(): Milpa\Command\Effect\EffectProfile

Nothing changes, so undoing DOES NOT APPLY — and the contract says so instead of staying silent. It used to say `Guaranteed` backed by the prose «nothing-to-roll-back», which is a different claim: `Guaranteed` promises a tested inverse and buys lower scrutiny with it. A read has no effect to take back, so it has no promise to make — {@see Reversibility::NotApplicable} says that, and `EffectProfile` now refuses the pair that said both. `EffectProfileTest` ties this to {@see EffectProfile::readOnly()}: the two must agree, because two answers to «what is a read made of» is exactly the second source of truth this attribute exists to remove.