Add decompose_audit(audit_path) to teaching/math_contemplation.py.
Groups audit_brief_11.json refusal rows by
(refusal_reason, missing_operator), emits one
MathReaderRefusalShapeProposal per group of >=2 rows, each carrying a
4-step ReasoningTrace (observation -> grouping -> hypothesis ->
conclusion).
Determinism:
- Group iteration sorted by (refusal_reason, missing_operator).
- Evidence per group sorted by case_id.
- Output tuple sorted by proposal_id.
- 10x rerun -> byte-identical proposals + trace_ids.
Pure read-only: audit file is not mutated, no proposals written to
disk, no chat/field/generate/algebra imports.
Tests (tests/test_adr_0172_w2_decomposer.py): real-audit emission,
determinism (10x), evidence floor, change-kind dispatch over all four
heuristic branches, four-step trace, case_id sort, proposal_id sort,
empty input -> empty tuple, unmapped operator skip, missing file ->
FileNotFoundError, no-mutation contract.
Added to core test --suite teaching.