Drop bmad-distillator integration from bmad-product-brief (finalize step,
update mode, headless JSON, constraints) and clean up customize.toml comments.
Distillation is the wrong layer — story self-containment via epic solution
design docs is the right answer for downstream context.
Also commit pending bmad-prd changes: working mode selector (Express vs
Facilitative), open-items triage into phase-blocking/resolvable/deferred
buckets, persistence wording fix, and facilitation-guide reference.
1a88f001d5