Add MiniMax-H3 Ref2VA Turbo adapter support

[a-github-name]

Summary

• add a managed, immutable pin for LightX2V's MiniMax-H3 Ref2VA Turbo 4-step v0.1 LoRA
• route H3 adapters by FL2VA versus Ref2VA task and preserve the published Ref2VA recipe
• materialize the compact Ref2VA transformer to resident BF16 before fusing all 312 PEFT LoRA pairs
• add task-aware preflight diagnostics, CLI validation, tests, changelog notes, and usage/provenance documentation

Why

Mere.run previously treated every MiniMax-H3 adapter as FL2VA-only and rejected adapters whenever ordered Ref2VA references were present. LightX2V now publishes a dedicated Ref2VA Turbo adapter, so the runtime needs to select the Ref2VA base, require references, and fuse the adapter into resident BF16 weights without changing the existing compact checkpoint or compiled denoising path.

Runtime behavior

The new managed adapter is:

minimax-h3-lightx2v-ref2v-4step-v0.1

It is pinned to upstream revision 5d1d4829fe614c1b93fcfd9cc7718e9ba71f73e1, exact size 1,383,677,768 bytes, and SHA-256 9e642fc8749c74f8da5e2382877ab5c7aa37b9a73b7fd0d6d457bd1b3cb1ae99.

Ref2VA Turbo requires at least one ordered image or video reference and resident BF16 transformer weights. Explicit --h3-weight-mode quantized requests fail preflight with a focused diagnostic. The adapter selects the published four-evaluation schedule, video/audio shifts 12/3, and LightX2V alpha 8.

Validation

• rebased on origin/main at 395088ee
• ./scripts/check.sh
  • strict SwiftLint: 0 violations
  • 2,825 tests passed
  • 206 fixture-gated tests skipped
  • 0 failures
• managed adapter pull downloaded and independently re-verified the exact byte count and SHA-256
• real native H3 Ref2VA smoke completed:
  • compact INT8 base loaded and materialized to resident BF16
  • ordered image reference encoded
  • all four denoising evaluations completed
  • video and audio decoded and exported
  • output readback: H.264 512x320, 22 frames at 24 fps, stereo AAC at 32 kHz

Licensing

The adapter is Apache-2.0. The MiniMax-H3 base-model Community License and its geographic/use restrictions remain unchanged.