Honor required request options in native Studio

[JoeMattie]

Summary

• propagate required request-option metadata from model specs into native Studio
• label required lyrics and reference transcripts correctly
• reject blank required fields before model loading or task submission
• regenerate the embedded native UI bundle

Why

MiniMax Music3 declares lyrics as required and rejects empty lyrics at runtime, but Studio labeled lyrics optional and omitted the field when blank. That made prompt-only submissions fail at the server. Studio now uses model-spec metadata as the source of truth, which also honors GLM-TTS's required reference transcript.

Port notes

This ports the applicable review fix from 717fade onto the implementation merged by #243. The other findings are already satisfied or no longer present on this branch: it uses a portable kTwoPi, retains runtimes when mem_saver=false, publishes a valid 32 MiB weight-context default with min: 1, and uses the file-based audiocpp_gguf converter instead of a raw stdio helper.

Validation

• npm run check
• npm run build
• cmake --build build/linux-cuda-release --target engine_model_minimax_music3 --parallel 4
• python3 tools/check_loader_catalog_sync.py --self-test
• python3 tools/check_loader_catalog_sync.py

[0xShug0]

@JoeMattie Merged, Thanks!