F414 production and verification contract

Producer
- compiler/ContinuationLowering.cpp
- MultiLatchLoopMemoryPhiCertificate
- multiLatchLoopMemoryPhiInitialization
- multiLatchLoopMemoryPhiRecord
- bounded-multilatch-loop-memoryphi-byte-lane-fixed-point
- symcc-loop-memoryphi-byte-lane-induction-v4
- mutually-exclusive-backedge-transfer

Consumer and runtime
- util/live_continuation.py
- LiveContinuationExecutor._multilatch_loop_memoryphi_fixed_point_initialization
- exact base/strided/multi-latch capability closure
- direct CFG, true-first decision-tree, dominance, and scalar PHI edge-copy replay
- closed scalar guard-expression provenance and exact integer width/range replay
- header MemoryPhi incoming block/access/kind identity
- complete versus recurrence-reachable writer aliases
- finite monotone byte-lane union, stability round, and complete alternatives
- bound capacity and whole-domain no-wrap proof
- path-local byte-init bitmap authority

Production fixtures and checker
- test/live_multilatch_loop_memoryphi_fixed_point.ll
- util/check_live_continuation_lowering.py
- benchmark/generate_multilatch_loop_memoryphi_fixture.py

Independent semantics and mechanism cost
- benchmark/check_multilatch_loop_memoryphi_oracles.py
- benchmark/benchmark_multilatch_loop_memoryphi.py
- test/test_multilatch_loop_memoryphi_fixed_point.py

Documentation and diagram
- docs/codex/research-progress/Multi_Latch_MemoryPhi_Fixed_Point_F414_2026-08-16.md
- docs/codex/diagrams/multilatch-memoryphi-fixed-point-f414.svg
- docs/codex/diagrams/multilatch-memoryphi-fixed-point-f414.png