fix: harden model catalog projections

backend/src/pi/provider-smoke.ts

@@ -79,6 +79,7 @@ export function createPiProviderSmoke(
         || catalog.defaultSession !== null;
       const catalogModel = catalog.sessionModels()
         .find((entry) => entry.provider === canonicalProvider && entry.model === model);
+      const upstreamModel = catalogModel?.upstreamModel ?? model;
       const credentialName = catalogModel?.authentication.mode === "secret_env"
         ? catalogModel.authentication.apiKeyEnv
         : undefined;
@@ -130,7 +131,7 @@ export function createPiProviderSmoke(
       const capabilityGuard = failOnUnexpectedCapabilities(rpc);
       const turn = async (): Promise<void> => {
         requireSuccessfulResponse(await rpc.request({
-          type: "set_model", provider: canonicalProvider, modelId: model,
+          type: "set_model", provider: canonicalProvider, modelId: upstreamModel,
         } as object & { type: string }));
         requireSuccessfulResponse(await rpc.request({
           type: "set_thinking_level", level: reasoning,