whetstone_DSL/docs/gap_hunt_fullstack_multifile_2026-02-26.md

Fullstack + Multi-file Gap Hunt - 2026-02-26

Runs:

• Baseline AB-only: logs/taskitem_runs/challenging_fullstack_multifile_20260226
• Production-enabled recheck: logs/taskitem_runs/challenging_fullstack_multifile_20260226_r5
• Parity-gated production recheck: logs/taskitem_runs/challenging_fullstack_multifile_20260226_r6
• Repair-augmented parity recheck: logs/taskitem_runs/challenging_fullstack_multifile_20260226_r7

High-Density Findings

• total_runs=12
• Path A ready: 50%
• Path B ready: 50%
• C++ readiness in this set: 0% (Path A and Path B)
• Python readiness in this set: 100%
• Token ratio PathB/PathA: 14.15x

New Gap Signals

• GR-016 Multi-file transactional closure gap

  • deterministic generation struggles when changes must span tightly-coupled file sets with rollback semantics.

• GR-017 Full-stack contract propagation gap

  • backend/frontend/schema/docs co-evolution lacks robust cross-layer consistency guarantees in deterministic path.

• GR-018 Performance/security/rollout constrained refactor gap

  • changes with explicit SLO/security/rollout constraints are under-enforced as first-class execution contracts.

Suggested Next Sprint Tranche

• 217: multi-file edit graph + required-artifact closure gate
• 218: full-stack contract propagation gate (OpenAPI/sdk/frontend sync)
• 219: migration/backfill/rollback hard gate with data-safety evidence
• 220: security propagation + deny-by-default cross-layer gate
• 221: SLO budget and rollout-choreography strict enforcement

Post-217-221 Recheck (r5)

• fullstack_contract.invalid_runs=0 with strict-mode checks enabled.
• Production loop now runs across this set (RUN_PROD=1) and reports:
  • ready_runs=12/12
  • false_green_candidates=0
  • ab_prod_divergence_count=6
• Remaining blocker is not contract presence; it is execution-path divergence:
  • C++ AB readiness remains 0% while production reports ready for same C++ rows.

Post-222-224 Parity Recheck (r6)

• parity mode enabled (REQUIRE_AB_PARITY=1)
• unresolved divergence now closed:
  • ab_prod_divergence_count=0
• safety gate now blocks inconsistent C++ rows:
  • ab_consistency_blocked_count=6
• practical effect:
  • production ready drops from 12/12 (r5) to 6/12 (r6), matching only non-divergent rows.

Post-225-227 Repair + Parity Recheck (r7)

• deterministic path-B repair layer enabled for C++/Go/Rust transpile artifacts.
• parity closure metrics:
  • ab_prod_divergence_count=0
  • ab_consistency_blocked_count=0
• hard suite headline:
  • Path B ready: 12/12 (100%)
  • production ready: 12/12 (100%)