Report actual inference smoke test destinations

internal/llm/openai_compatible_client.go

@@ -193,6 +193,9 @@ func resolveAPIKey(target domain.ExecutionTarget) string {
 	return apiKey
 }
 
+// InitialEndpoint returns the frozen request URL before redirects.
+func (p *PreparedGeneration) InitialEndpoint() string { return p.endpoint }
+
 // Execute dispatches one attempt. The returned response is non-nil only when
 // the successful envelope contains a usable first choice.
 func (p *PreparedGeneration) Execute(ctx context.Context) AttemptOutcome {