Adds empirical coverage of the three ADR-0219 checkpoint sub-steps where
a process kill can occur: PARTIAL_GEN (gen dir exists but partially written),
FULL_GEN_BEFORE_SWAP (all four files written but current pointer not yet swapped),
and AFTER_SWAP (clean-commit control case, already covered by rec_a/rec_b).
For each of the two non-trivial cut-points the harness:
1. runs a probe soak to commit reboot_turn turns,
2. injects the corresponding orphan shape,
3. reads the on-disk manifest to confirm the loader follows `current` and reads
the committed generation (not the orphan),
4. runs two independent recovery soaks (each injecting the same orphan at the
reboot boundary) and verifies their post-reboot trace_hash tails converge,
5. checks versor_condition < 1e-6 throughout every recovery soak.
New predicate evaluate_p4_arbitrary_interruption (predicates.py) expresses
this as a PredicateOutcome with a CutPointEvidence carrier. It has:
- holds gate: recovered_turn_count == expected (orphan was ignored)
- holds gate: tail_hashes_a == tail_hashes_b (two recoveries converge)
- holds gate: all versor_conditions < ceiling (closure throughout)
- bites gate: tested by four mutation tests (wrong count, diverging tails,
vc violation, empty tails)
contract.md: all spec predicates P1-P5c are now covered (NOT_COVERED is empty).
Per CLAUDE.md schema-as-proof: every predicate gate is verified by a *_bites
mutation test — 9 tests total (3 injection unit, 2 real-soak holds, 4 bites)
all pass in 109s.
f5c6914d00