Replace the position capture cutoff with a camera-relative dark threshold
shared by every backend, and carry explicit outcome/reason provenance
through the ray, RayPool, adaptive mesh, lens-map and replay paths.
- eval/eval_slab return SpacetimePointStatus; remove SPACETIME_RAY_CAPTURED
and the Schwarzschild capture radius; decouple observer construction from
ray position.
- RayEndpoint stores RayOutcome/RayReason plus the last trusted state;
budget exhaustion is retryable UNRESOLVED, data/integration failures are
INCOMPLETE.
- Normal dark terminal is L - L0 >= --dark-threshold (default 8), with L0
taken at the camera event and kept distinct from the worldtube entry
energy; photon energy and frequency ratio are never reset.
- Implement E/D/U triangle decisions with merged budget retries, persistent
probe witnesses promoted in place by vertex identity, conformity settling,
and approximate-black boundary provenance with achieved-scale statistics.
- Add RayPool continuation state and per-ray step budgets.
- Bump lens-map to v2 with explicit end/outcome/reason, approx_black,
threshold/retry/geometry provenance and per-frame retry counts; reject v1.
- Gate production output on incomplete/error results, overridable with
--allow-incomplete.
- Update AGENTS.md, the design document and usage docs; add the termination
oracle and regression coverage.
make -B -j4 BUILD_TYPE=Debug test passes with bit-identical reference HDRs.