S1-S3 and S5-S8 pass; S4 is prepared but deliberately unfiled pending user
sign-off (tasks.md 7.4 stays unchecked).
Two bugs surfaced by running the composed pipeline against real data rather
than synthetic fixtures, both in load-bearing places:
audit-snapshot: cost_per_invocation folded to 0 when a candidate had zero
invocations in a window, so a step that simply did not run reported -100% and
direction() called it `shrunk`. That is the quiet-window artefact FR-5.4 exists
to prevent, one level up from absolute tokens, and it contradicted direction()'s
own docstring. It is now None, metric_delta marks the pair `unmeasured`,
direction returns a new `unmeasured` status, and the pages render "not run".
tests/calibration/mask-worktree-audit.py: recomputed script_loc from scripts
alone, silently dropping all 1051 LOC of worktree-discipline's hooks. Masking
one 272-LOC script appeared to remove 1323, taking script_coverage 0.353 -> 0.083
instead of 0.297, which let S3 pass partly on an artefact of the mask. The mask
now matches build_aggregate. S3 still flags the known cut `high` /
llm-over-script-digest on the corrected, harder input.
Both fixes carry regression tests; suite is 156 assertions, exit 0.
Oleks
105e9f5bae