Feature/replay

[JesusMcCloud]

• Matrix testing: bounded compact concurrency
  • CompactConcurrency.Shared(n) runs a compact block through one compact-wide worker budget, so nested virtual
    layers can no longer multiply coroutine counts; CompactConcurrency.Layered keeps per-layer behaviour.
    Set it per compact block or via defaultCompactConcurrency.
• Matrix testing: replay failing cases
  • Failure reports — real test-tree leaves and compacted virtual rows alike — now include a copy-paste-ready
    Error replay info block whose lines are valid property / data arguments.
  • Pin a property layer to recorded cases with replay = ReplayInput(seed, iteration), or
    replays = listOf(...) for several seed/iteration pairs at once; pin a data layer with replayIndex /
    replayIndexes. Pasting the reported lines re-runs exactly the failing case(s).
  • replay is independent of a layer's seed (deterministic full run vs. selecting recorded cases).
  • Replay info captures the full enclosing layer chain and records data indexes independently of nameFn.