test: preserve scalar receipts when optional shear probes fail

tests/validation/taylor_green/run_case.py

@@ -25,7 +25,7 @@ NESTED_SHEAR = "nested_shear_n128"  # fixed three-level/two-region shear preset
 SHEAR_NESTED_SHA256 = "fa6cfe87fb4df8c6d732c637c885276833c81973b950c7724d734f8fc350bcb0"
 TWIN_SHEAR = "twin_shear_n128"  # depth-2 twin: nested L0->L1 boxes without L2
 SHEAR_TWIN_SHA256 = "1cbf37f18e89aea577581631c4565f51e68d22a3739b698816ef64acbf2b2bb4"
-SHEAR_PROBES_SHA256 = "53ba8af8ac9c8078c40f84488c7ade4c11ccc91dd1fc275ff806042e9af30166"  # signed interface-probe mechanism diagnostic
+SHEAR_PROBES_SHA256 = "e2e6490d281cc275f448dc6d6ea7b9b4407cc74a51e9256b86c08c8626b89b76"  # signed interface-probe mechanism diagnostic
 
 
 def flow_functions(flow="taylor_green"):
@@ -382,9 +382,16 @@ def main():
                 run.step(step - run.step_count)
                 if step in probe_steps:
                     trace = report["probe_trace"]
-                    trace["steps"].append(probe_root[step])  # root-physical step
-                    trace["values"].append(shear_probes.sample(
-                        (run.download(),) if args.depth == 1 else run.download(), probes))
+                    if "error" not in trace:
+                        arrays = (run.download(),) if args.depth == 1 else run.download()
+                        try:
+                            values = shear_probes.sample(arrays, probes)
+                            shear_probes.validate_row(values, len(probes))
+                        except (ValueError, ZeroDivisionError) as error:
+                            report["probe_trace"] = dict(error=str(error))
+                        else:
+                            trace["steps"].append(probe_root[step])  # root-physical step
+                            trace["values"].append(values)
                     if step not in main_steps and step not in early_steps:
                         continue  # probe-only step: no qualification metrics
                 row = sample(run, masks, step, args.n, cfg.viscosity, initial_mass,
@@ -439,7 +446,7 @@ def main():
                         ),
                         flush=True,
                     )
-    if args.probe_trace:
+    if args.probe_trace and "error" not in report["probe_trace"]:
         try:
             report["probe_trace"]["bytes"] = shear_probes.validate(report["probe_trace"])
         except ValueError as error:  # keep the scalar receipt; drop an invalid trace