feat: add TokenDance channel

[zijiren233]

Add a dedicated TokenDance channel (type 59) with the official default endpoint https://tokendance.space/gateway/v1, API key guidance, and links to its documentation and public model catalog.

The adaptor reuses the OpenAI implementation for chat completions, Responses, embeddings, image generation and editing, and Anthropic/Gemini request conversion. Supported modes are limited to those paths; model IDs are configured according to the catalog's supported_protocols. Channel registration and Swagger enums are updated.

Validation:

• 762 tests passed across model, controller, adaptor registry, and OpenAI packages; the new adaptor compiles.
• golangci-lint reported no issues in the affected packages.
• Verified endpoint paths against official documentation and successfully fetched the public model catalog.
• Authenticated inference was not tested.