[Model] Accelerate MiniMax-H3 end-to-end inference

[lishunyang12]

#7415
Spliting into

ID	Scope	Depends on
P1	Move H3 VSA policy into the model directory; keep shared interfaces generic #7535	—
P2	Exact AdaLN cache, builder, and adapter/schedule identity checks	P1
P3	DiT MXFP8 projections and SwiGLU fusion	P2
P4	Generic Sage provider and H3 VSA integration	P1
P5	Chunked video D2H, bounded CPU staging, and MP4 output pipeline	—
P6	VAE MXFP8, paired/mixed batching, gather and audio overlap	P3, P5
P7	Optional generic FlashInfer Ulysses/RDMA transport	P1
P8	Gate projection overlap, QK/V splitting, early Q preparation, coarse/fine overlap, and O producer lookahead	P3, P4, P7
P9	Final preset, reproducible recipe, and cumulative optimization results	P6, P8

Module layout and validation

The H3 directory now has 39 Python modules instead of 45. Component quantization policy, VAE batching, VAE parallel output and VSA producer lifetime are consolidated; the model-specific VSA entry is attention/vsa.py. Shared platform selection, transport and operators retain their owners. No VDN implementation or new dependency is added.

At 7ba27060, the related regression group reports 337 passed, 20 failed. All 20 failures also occur in the pre-change dda16f4b checkout after removing its unsupported OffloadPlan.resident_offload_submodules keyword solely to allow imports (that comparison reports 327 passed, 21 failed). Nine implementation-adapter tests are brought over from P1, and its dispatch typing fix resolves the remaining one-test difference. The outstanding failures concern media output/capability contracts and fixtures missing acceleration state; this draft is not merge-qualified.

Pre-commit passes. All 61 moved function/class ASTs match after explicit import and symbol normalization. The consolidated modules import with optional kernel-provider imports blocked. No full-model E2E or VDN qualification was run.

[hsliuustc0106]

This PR touches vllm_omni/diffusion/, tests/diffusion/, docs/user_guide/, recipes/MiniMaxAI/, tools/minimax_h3/ (51 files). Based on CODEOWNERS coverage of the changed files, the most-related reviewers appear to be:

@wtomin @Bounty-hunter @fhfuih

Could one of you take a look when you get a chance? Thanks!

[hsliuustc0106]

Ready for full review when draft status is removed and the merge conflicts are resolved.