Track A is the natural primary lock — frame-11 EINVAL has carried for
three iterations; iter3's rig + Y2 instrumentation make the diagnosis
loop short. Other candidates: DEBUG sweep (B, iter1+2+3 backlog), mpv
libplacebo segfault (C, iter3 carryover), perf binding cell (D, iter1+2+3
backlog), V4L2_MEMORY_DMABUF Option B (E, iter2 carryover), multi-context
safety (F, Sonnet review 9.6), Mozilla bug filing (G, gated on operator).
Recommended: A primary, pair with B (cleanup) or D (perf anchor).
Phase 1 lock awaits user candidate pick.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
