Add LongCat-2.0 as a first-class OpenAI-compatible provider preset so it can be
selected by name in the setup wizard / `zero providers setup longcat` instead of
hand-entering a custom endpoint.
LongCat-2.0 is Meituan's open, OpenAI- and Anthropic-compatible model. This
wires the OpenAI-compatible transport:
base URL: https://api.longcat.chat/openai (Zero appends /chat/completions)
model: LongCat-2.0
auth: Bearer via LONGCAT_API_KEY
Purely additive — one descriptor plus its catalog/onboarding tests and a README
env-var line; no shared plumbing is touched, so existing providers are
unaffected. Placed with the other OpenAI-compatible third parties (after
moonshot), below the first-party providers.
Verified: go build / vet / test green (catalog + cli onboarding), gofmt clean,
and `zero providers catalog` lists the descriptor with the correct fields.
Endpoint is wired by-spec from LongCat's published docs; a live completion still
needs a real LONGCAT_API_KEY to confirm.
KRATOS
b4275e3504