XY-982 qmd debug ergonomics Dreaming retest

[yvette-carlisle]

Summary

• Add the June 19 qmd debug-ergonomics Dreaming retest report and machine snapshot.
• Confirm the qmd debug edge remains unchanged: qmd keeps default top-k/short CLI replay, while ELF keeps the narrow operator-debug trace/stage visibility wins.
• Update README/index routing and add a focused snapshot regression test for the claim boundaries.

Benchmark

• cargo make real-world-job-operator-ux-live-adapters: pass; ELF 6 pass/0 wrong_result, qmd 0 pass/6 wrong_result in the narrow operator-debug live slice.

Validation

• jq empty apps/elf-eval/fixtures/report_snapshots/2026-06-19-qmd-debug-ergonomics-dreaming-retest-report.json
• cargo test -p elf-eval --test real_world_job_benchmark qmd_debug_ergonomics_dreaming_retest_report_preserves_qmd_edge -- --test-threads=1
• cargo make fmt-check
• cargo make check-docs
• decodex docs check
• cargo make lint

Boundaries

• Does not claim broad ELF-over-qmd superiority.
• Does not treat qmd live operator-debug wrong_result rows as evidence that the qmd default top-k/replay edge is gone.
• Leaves expansion, dense/sparse contribution, fusion, and rerank parity unproven until comparable artifacts are emitted.