* backend
- constant/endpoint_type.go
• Add EndpointTypeMidjourney, EndpointTypeSuno, EndpointTypeKling, EndpointTypeJimeng.
- common/endpoint_type.go
• Map Midjourney / MidjourneyPlus, SunoAPI, Kling, Jimeng channel types to the new endpoint types.
* frontend
- ModelPricing.js
• Add “Supported Endpoint Type” column.
• Implement renderSupportedEndpoints with `stringToColor` for consistent tag colors.
These changes allow `/api/pricing` and model lists to return accurate
`supported_endpoint_types` covering all non-OpenAI providers and display
them clearly in the UI.
No breaking changes.
