fix(server): await providers before catalog reads - #46066

Why

An initial provider list or lookup could read the empty Catalog before configured plugins finished registering providers. The same request would then succeed after a model endpoint happened to flush plugin initialization.

What Changes

provider.list and provider.get now use the existing lazy plugin-readiness policy before reading the Catalog:

Scope

Only the two provider catalog endpoints change. Their Protocol already declares the readiness error, so no client regeneration is required.

Verification

cd packages/server
bun run test test/provider.test.ts test/handler-policy.test.ts
bun typecheck
git diff --check origin/v2...HEAD

• 5 focused tests passed.
• Server and workspace typechecks passed.
• Independent final review found no issues.