Support ZImagePixelSpace (NextDiTPixelSpace) — Z-Image Turbo model variant

[Evarixe]

ZImagePixelSpace (NextDiTPixelSpace) support

Error with Z-Image Turbo (ZIT) + lumina_2 model_type:
RuntimeError: Given normalized_shape=[2560], expected input [*2560], got [1, 44, 3840]

Root cause: teacache_lumina_forward is patched onto NextDiTPixelSpace but was written for NextDiT. Three differences:

1. patchify_and_embed returns 6 values in NextDiTPixelSpace (adds timestep_zero_index) — TeaCache unpacks only 5
2. Pixel-space formula (x - neg_x0) / timesteps is bypassed
3. Different _forward → forward wrapping via WrapperExecutor

Proposed fix: Add teacache_lumina_pixelspace_forward, dispatch via hasattr(diffusion_model, "dec_net").

Impact: ZIT uses dual-pass KSampler (~5s on RTX 5090 at 1MP). TeaCache 1.7x → ~3s.

Model: ZImagePixelSpace(Lumina2) → NextDiTPixelSpace(NextDiT), inner_dim=3840, Qwen3-4B CLIP (2560).