Adds explicit ProductionUseCase<SignInInput, SignInOutput, AuthManifest["useCases"]["signIn"]>
type annotation to wrappedSignIn in bind-production.ts. To satisfy the Instrumented & Captured
intersection requirement, withSpan gains a brand-preserving overload so composing
withSpan ∘ withCapture returns Instrumented<F> & Captured<F>.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>