Extract TwoStageZImagePipeline shared base from QwenZImagePipeline so all three
profiles are siblings, not a chain. Add ChromaZImagePipeline on that base with
diffusers ChromaImg2ImgPipeline bf16, neutral calibrated prompt, guidance 5.0,
four effective steps with Diffusers truncation compensation, no Canny.
Flat vendor floors from the 2026-08-29/30 oracle calibration across OpenAI
(0.09), Microsoft InvisMark (0.125), Google (0.40), Meta Content Seal (0.17),
seed-stability verified on Meta, full-path face-stage interaction clean through
the Gemini oracle. Research record in docs/chroma1-engine-research.md with the
matched-strength addendum showing Chroma1 regenerates better per unit strength
but its boundaries scatter wider than qwen's. Fix text-manifest guard to reject
chroma-zimage at the boundary, update all profile references from 'both' to
'all three' across src, docs, README, and python-api.
