sampler: Support thereafter of zero ( 1033)
sampler: Support thereafter of zero ( 1033): a task in repo2rlenv-commit-runtime-v2 (Harbor dataset). Title: Sampler panics when thereafter is set to 0
The task
**Title:** Sampler panics when `thereafter` is set to 0
Part of FineEnvs/repo2rlenv-commit-runtime.