Ship Grok 5×8 white/IDS packing and universal IDS/factsheet plumbing while
keeping DEFAULT_MODEL_BASES Fable-only: live pure-image Grok is not
Fable-level; image+factsheet is the working exact path.
Chart shows Grok as a text-window series only (no Grok+pxpipe overlay) and
Fable as the measured pxpipe density point. Add Codex-path quality harnesses
and receipts (multi-seed, fix-matrix, shipped smoke).
The GPT tests drive gpt-5.6-sol, which is intentionally outside the
built-in default scope (Fable 5 only). Without pinning, the file's
result depended on the developer's ambient PXPIPE_MODELS — passing
locally but failing in CI's clean env. Snapshot/pin/restore, same
convention as proxy-usage.test.ts.
Steven Chong