Malte Langkabel
a45df902aa
Introduces the state-checksum machinery the replay feature rests on, and a test that proves the simulation is deterministic for a given seed/binary. - StateChecksum: FNV-1a Hasher (bit-pattern float hashing, -0 normalization, length-tagged strings) plus a portable mt19937 state fingerprint. - BeltSystem/BuildingSystem: appendChecksum(Hasher&) folding transport and building/site/occupancy state in deterministic (sorted/insertion) order. - Simulation: rngFingerprint() (cheap, for the future file checksum) and computeStateChecksum() (full state: RNG, scalars, wave/schematic/unlock state, subsystems, and ECS position/health/facing/body/scrap/identity). - DeterminismTest: Hasher unit tests, RNG-fingerprint tests, and a double-run test asserting identical per-tick full-state checksums from one seed; plus a different-seed divergence guard. Exit criteria met: double-run determinism test passes; full suite green (334 cases / 3346 assertions). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01DUsFgd2Ga6pmLz8giS8WUn