.bnnpack v2 design sketch (W5.T05) — not implemented

Field	Value
Status	Design only (v1 remains shipping format)
Date	2026-07-25

Goals

• Ternary bitplanes + binary in one container
• Richer meta (policy, sensitivity summary, HW probe)
• Content hashes per tensor for untrusted-file warnings
• Forward-compatible schema version field (already in v1 header)

Non-goals for v2.0 draft

• Full safetensors interop (W5.T06 follows)
• ONNX (deferred — docs/MOONSHOT_DEFERRALS.md)

Migration

v1 readers must reject unknown major versions loudly. v2 writers may emit v1-compatible subset when ternary unused.

Next step

ADR under docs/adr/ when implementing; keep round-trip tests green.