Same session-scoped line admission used by the eager scene walk.
OptionallodOptional LOD-group registry for the lazy-level fallback: lazy
substitutive levels never join the loader maps (they're registry-driven
— see load-lod-group-node.ts), so when a failed path resolves to no
map entry the retry re-kicks the level's ensureLoaded through
retryLazyChildByNodePath instead of discarding the failure.
Optional so headless/test ctxs without a registry keep working.
OptionalclearClear the owning SceneLoader's archive latch before a lazy retry.
Narrow context the retry helpers need from the orchestrator. Keeps the helper independent of SceneLoader internals.