[chengyongru]

Summary

• Move WebUI provider model catalog classification onto ProviderSpec metadata with an auto default.
• Keep only the real explicit catalog override in the provider registry: skywork remains official even though it is a gateway.
• Derive unsupported OAuth, transcription-only, and non-OpenAI-compatible provider model lists from existing provider flags/backend.
• Remove duplicated WebUI provider classification sets.

Impact

This reduces the number of places touched when adding providers. Existing OAuth providers still remain selectable/login-capable, but their model list loading remains unsupported, matching prior behavior.

Validation

• uv run --extra dev pytest tests/webui/test_settings_api.py -q
• ruff check nanobot/providers/registry.py nanobot/webui/settings_api.py tests/webui/test_settings_api.py

[Re-bin]

LGTM. This is a clean WebUI settings refactor: model catalog behavior now derives from provider metadata and generic provider traits instead of a duplicated hard-coded list in the settings API. I checked the full provider classification shape, including the Skywork gateway exception, local providers, OAuth providers, transcription-only providers, and native backends.

Validated locally:

• python -m pytest tests/webui/test_settings_api.py -q
• python -m ruff check nanobot/providers/registry.py nanobot/webui/settings_api.py tests/webui/test_settings_api.py