Make Provider.Model api.url optional to match providers with a native SDK #205

Context

Provider.Model in packages/cli/src/provider/provider.ts declares api.url as a required z.string(). Providers with a native SDK (for example anthropic, openai, amazon-bedrock, azure) resolve their own endpoint, so their models have no URL:

• Before feat(provider)!: replace models.dev with a static model catalog (#40) #202, fromModelsDevModel set url: model.provider?.api ?? provider.api!, which was undefined at runtime for these providers.
• Since feat(provider)!: replace models.dev with a static model catalog (#40) #202, these models in catalog.json leave out api.url (600 of 1354 models).

Runtime is fine: loadBaseURL treats a non-string URL as "no base URL". But the declared schema does not match the data. test/provider/catalog.test.ts has to relax url to optional to validate the catalog. Raised in the #202 review (finding "Model schema requires api.url; 600 catalog models omit it").

Proposal

Make Provider.Model.api.url optional, so the type and schema say what the data holds. Update the consumers that assume a string. Regenerate the SDK types under packages/sdk/src/gen (Model.api.url becomes url?: string) and note the type change for SDK users.

Acceptance criteria

• Provider.Model.shape.api.shape.url is optional, and every catalog model parses with plain Provider.Model (the relaxed schema in catalog.test.ts is removed).
• bun turbo typecheck passes with no non-null assertions added for api.url.
• The regenerated SDK types are committed, and the change is called out in the release notes.