v0.1.8

Adds the crossed (vignette by replicate) bootstrap used for every interval in the current manuscript (crossed_boot.py), its coverage simulation (coverage_sim.py), exact one-sided bounds for zero-observed floors (fixed_case_bounds.py), and an isolated-call sensitivity arm for endpoint A (claude-haiku-4-5, one claude -p call per prompt, ten replicates; claude_cli_answerer.py, haiku_iso_floor.py, experiments/floor16_haiku_iso). README results updated to five-action floors with crossed intervals and the new paper title. verify_paper_numbers.py checks 407 claims.