Compare time value objects by value, never by instance.

[gustavofreze]

Instant and LocalDate declared the value-object contract while holding a DateTimeImmutable, and structural equality compares a property that is not itself a value object with ===, which on an object is identity. Two instances of the same moment were never equal, their hash codes never matched, and neither did any value object that carried one as a property. Duration had the same defect through Internal\Seconds, and Timezone did not declare the contract at all.

Overriding equals would not have been enough: ValueObjectEquality walks the properties by reflection and never calls equals, so a wrapper would keep comparing the inner DateTimeImmutable by identity. The state is what had to change, so Instant and LocalDate now hold their canonical text, and IsoMoment and IsoDate own the conversion in Internal, where the style rule allows the helpers.

Fixing LocalDate surfaced a second defect. Its parser filled the time of day from the clock of the moment it ran, so two instances of the same date built a second apart reported isAfter and isBefore as true at the same time. Holding the canonical date removes the wall clock along with the identity comparison.

Both createFromFormat calls are gone with it, which removed one PHPStan suppression instead of adding another.

Two notes for consumers. Timezone gains equals and hashCode, which is new public surface. toDateTimeImmutable now returns a new object on every call rather than the stored one, so identity comparisons of its return value change; value comparisons and every other behaviour are unchanged.

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• Tests added or updated.
• Documentation updated when applicable.
• make review passes.
• make tests passes.