Implements the external auditor ADR-0114a Obligation #10 requires:
"Every SolutionTrace.steps[*].pack_lemma_id resolves to a real
lexicon entry in the domain's operator pack." The solver enforces
this at solve time; this PR audits it from outside.
New module core/capability/pack_provenance.py:
- _load_lexicon_lemmas(): independent re-read of pack lexicon
- _parse_lemma_id(): <pack_id>:<lemma> shape parser
- validate_lane(): re-runs candidate-graph pipeline on a B-lane's
cases, walks every solver step, validates pack_lemma_id parses
AND resolves to a lexicon entry. Per-case + per-lane verdict.
- emit_provenance_report(): deterministic artifact emission.
CLI: core capability pack-provenance (added to core/cli.py).
Writes evals/obligation_10_pack_provenance/<lane_id>.json.
Empirical verdict on current main (post-PR #186):
lane: B3_bounded_grammar
cases_total: 50
cases_validated: 25 (every expected-correct B3 case)
cases_skipped_unsolved: 25 (refusal-expected probes — by design)
cases_violated: 0
obligation_10_passed: True
5 distinct lemma_ids observed (add, subtract, transfer,
compare_additive, compare_multiplicative) — all resolve to
en_arithmetic_v1. The other 3 op kinds (multiply, divide,
apply_rate) ratify-at-solve-time via _resolve_pack_lemmas so the
obligation holds for them too if a future case exercises them.
Honest scope-limit: B3 only. B1 (symbolic equivalence) and B2
(teaching corpus) equivalents deferred to separate sub-ADRs —
B1 needs reframing (algebra normalization chain, not arithmetic
steps); B2 can use this same auditor signature once corpus
solver-trace exercise is confirmed case-by-case.
Composition with ADR-0131.4: orthogonal. Composite gate verdict
+ obligation #10 verdict + 4 other obligation auditors (when
they land) + reviewer signature → full ADR-0120 wire-up.
Trust boundary: read-only access to pack lexicon + B3 cases;
single deterministic write to artifact path. No dynamic imports,
no shell passthrough, no network. Pure deterministic auditor.
Tests: 19/19 in tests/test_adr_0114a_10_pack_provenance.py
covering lemma-id parser (well-formed + malformed), lexicon loader
(real pack + every failure mode), lane validator (passes on real
B3 + refuses on missing pack/cases + skips refusal-expected cases
without false violation), determinism (report identical across
calls + artifact byte-equal).