Regression corpus

Set PROPERTY_DB to a directory and every falsified property records its failure there. On the next run the recorded failures are replayed first (unless the attribute pins its own seed): one that still fails is reported immediately for fast feedback, one that no longer fails — or that the property now discards via Assume::that() — is pruned. A property accumulates several past failures, so fixing the newest one does not lose the older ones.

A failure is recorded in one of two ways:

Entry	When	Replay	Reported as
Values	Every minimised argument is representable as data: null, scalars, arrays, enum cases, byte strings	One run with the exact recorded input	RegressionViolationException
Seed	Anything else — objects, closures, or in-body Gen::draw() values in the counterexample	The whole random phase, re-run with that seed	PropertyViolationException

Values entries are preferred: they cost a single run, and they keep working when the generation sequence shifts, because they carry the input rather than a recipe for regenerating it. Seed entries are the fallback and are dropped when the package's generation sequence changes (they would otherwise replay a different input under the guise of a regression). A values entry is also dropped when the property's signature no longer matches the recorded argument names — a renamed or added parameter makes the stored input a different input.

Storage is one small JSON file per property (<sha1(id)>.json, at most 8 values entries and 2 seed entries, oldest evicted first); add the directory to .gitignore.