Remove legacy Python WebUI

[mirek190]

Summary

Make the embedded native Svelte UI the repository's only browser interface and remove the superseded Python/Gradio and legacy realtime WebUI implementations.

Changes

• remove the Python/Gradio application, launch scripts, environment helpers, Python dependencies, tests, and generated-output placeholders
• remove the separate legacy realtime Python server and static browser client
• remove duplicate legacy voice assets now supplied by the native UI's embedded demo-voice bundle
• simplify webui/README.md around audiocpp_server --ui
• update root documentation, the SenseVoice contributor notes, the voice-directory example, packaging, ignore rules, and catalog comments
• regenerate the checked-in native single-file UI artifact from the current source

Scope boundary

This deliberately keeps tools/model_manager_v2.py and tools/model_manager_deprecated.py. They are repository-wide model preparation utilities used by the native server's Models workflow, not browser UI implementations. Replacing that model-manager layer can therefore be handled independently in a follow-up without mixing it into this UI cleanup.

User impact

• one maintained WebUI path: the Svelte frontend embedded in audiocpp_server
• no Python, Node.js, or Gradio is needed to run the packaged WebUI
• model preparation may still invoke the existing Python model-manager tools
• inference behavior and model implementations are unchanged

The cleanup removes about 16,100 obsolete lines and 48 legacy/related files.

Validation

• npm run check — 0 errors and 0 warnings
• npm run build — native single-file frontend rebuilt successfully
• native language and catalog JSON files parsed successfully
• python tools/check_loader_catalog_sync.py --self-test — passed
• python tools/check_loader_catalog_sync.py — runtime loaders, model specs, and model manager v2 are in sync
• Windows CUDA release audiocpp_server build — passed
• audiocpp_server --ui --backend cpu --port 18080 smoke test — /health reported UI enabled and / returned the embedded native interface
• git diff --check — passed

[0xShug0]

Thanks @mirek190! I'm building windows prebuilts for release 0.6. It seems that the prebuilts won't be affected by the cleanup so I will merge the PR after release 0.6

[mirek190]

sure

I am working how to get rid of model_manager_v2.py yet

[0xShug0]

Fresh: https://huggingface.co/MiniMaxAI/MiniMax-Music3

[mirek190]

Fresh: https://huggingface.co/MiniMaxAI/MiniMax-Music3

sick .....
We have to replace current implementation by this one :)

[0xShug0]

@mirek190 Merged! Thanks!