v1.38.0

principle-type-system-discipline almost never fired. Rewriting its description around the
nouns a user actually types moved it from 1/10 to 9/10 at n=10 — matching the control's rate.
The same rewrite method applied to principle-build-the-lever did not move it.

The shipped description read "Apply when designing types or a function signature in TypeScript,
Rust, Go, or other statically-typed code" — mechanism vocabulary, not language a prompt actually
contains. Rewritten to name the concrete shapes instead: "Apply when a struct, enum, or type can
hold an invalid combination of fields that shouldn't compile," dispatched at 9/10, matching the
control. principle-build-the-lever got the identical treatment — surfacing its own literal
nouns in place of mechanism language — and it did not move: 2/10, sitting exactly on the
pre-registered falsification floor, and the rewrite was reverted rather than shipped. A method
that fixes one skill's dispatch rate and fails to fix another is a real finding about the limits
of the description-rewrite lever, not a pattern to repeat blind — record both halves or the
failure gets silently forgotten the next time someone reaches for the same trick.

skill-mandate.sh now logs delegation counts per Stop, for measuring the breadth mandate's
effect on delegation behaviour going forward instead of only its blocks.

The Stop hook already computes dir_count/ext_count/task_count/named to decide whether to
block; this appends one line per evaluated Stop to a JSONL log (session_id,
checkpoint_index, the four counts, ts). Counts only — no paths, no file contents, matching
the discipline the mandates already apply before anything reaches a block message. Logs
unconditionally, blocks conditionally, so the log reflects the rate the mandate is trying to
move rather than only the cases it already caught. Opt-out VSTACK_NO_DELEGATION_LOG=1, same
shape as the existing VSTACK_NO_MANDATE escape hatch; VSTACK_DELEGATION_LOG overrides the
destination. Capped at ~2MB with tail-and-atomic-mv rotation to the last 5000 lines, checked
with one O(1) stat per Stop rather than a line count. Measured latency: 28.3ms with the logger
active vs 28.6ms without, over 60 samples at σ≈1.9ms — indistinguishable from zero.
tests/delegation-drift.sh (+ delegation-drift.py) is the accompanying analyser: pre-registered
thresholds, states its own reverse-causality confound, and reports NOT EVALUATED rather than a
rate below its eligible-window floor — the correct, expected result on day one, confirmed
against this machine's own data.