Extends the HA soak harness with --array-chaos-retry: submits an
array, kills the primary essentially immediately (before commit is
known), retries the identical submission against the new primary, and
hard-asserts exactly one committed instance results -- no silent loss,
no double-submit, no partial duplication across the array's full
index range.
Confirms (no production code changes needed) that the existing
single-job cross-primary dedup mechanism (bug-1419: client-side jobid
minted once and never re-sent on retry; server-side
jobid_range_exists()/inflight_range_try_add(), both genuinely
range-shaped over [base,base+array_size); xce_failover_classify()'s
idempotent-replay rule) generalizes correctly to arrays, treating the
whole range as one dedup unit rather than per-element.
No mutation-test RED phase against production code was performed
(correctly out of this task's boundary); reviewer compensated by
extracting the harness's own assertion logic into a standalone
mutation-harness with stubbed collaborators, confirming real
fail()-gated teeth on all four outcomes (clean/silent-loss/
double-submit/partial-duplication).
Live-verified across 4 independent fresh cluster deployments (2 by
implementer, 2 by reviewer), array sizes 6/10/15, 17 total chaotic
rounds, zero failures, genuine election/term diversity each time.
Task 6.2 of job-array-single-wal-record (Requirements 8.2, 8.3).
Rongsong Shen
c6138496bd