Captures the post-handoff-56 arc: H1 (ADR-0019) verified already shipped
(not "partial"); build-hygiene fixes (incremental off, line-tables debug,
cargo-sweep) cutting target/ from 38 GB to ~1.6 GB; and consolidating 25
integration crates into one `it` binary (disk win, not the predicted
speed win). Flags the new test layout (add tests under tests/it/ + a mod
line) and points the next session at H1a (ADR-0021) as the queued job.
claude@clouddev1