fix: keep synthesis progress active until result

app.py

@@ -82,9 +82,10 @@ def _model_assist_gpu(*, engine, result, narrative_text):
     return run_model_assist(engine=engine, result=result, narrative_text=narrative_text)
 
 
-# completed-step count for the frontend's 6-item checklist
-# (item 0 "uploading" is done once the request reaches us).
-_STEP_COUNT = {"extract": 2, "redact": 3, "chart": 4, "classify": 5, "synthesize": 6}
+# Completed-step count for the frontend's 6-item checklist. Keep the final
+# synthesis row active until the final payload is ready, because model assist
+# runs after deterministic synthesis on the ZeroGPU path.
+_STEP_COUNT = {"extract": 2, "redact": 3, "chart": 4, "classify": 5, "synthesize": 5}
 
 
 def _file_fields(trace_file: object) -> tuple[str | None, str | None]:

frontend/static/app.jsx

@@ -308,8 +308,11 @@ function App() {
         if (msg.type === "data") {
           const p = Array.isArray(msg.data) ? msg.data[0] : msg.data;
           if (p && typeof p === "object") {
-            if (typeof p.step === "number") setStep(p.step);
-            if (p.result) result = p.result;
+            if (p.result) {
+              result = p.result;
+            } else if (typeof p.step === "number") {
+              setStep(Math.min(p.step, PIPELINE.length - 1));
+            }
           }
         } else if (msg.type === "status") {
           if (msg.stage === "error") throw new Error(msg.message || "The analyzer failed on the server.");