u/cascade: track per-worker failures, annotate status, exit non-zero

scripts/u/cascade

@@ -79,7 +79,7 @@ for i in $(seq 0 $((count - 1))); do
         "$B" -name "$sid" -backend "$WB" -model "$WM" -keep \
             "You are a worker agent. Execute the following task exactly. Output only the result.
 
-$instruction" > "${tmpdir}/${sid}.out" 2>&1
+$instruction" > "${tmpdir}/${sid}.out" 2>&1 && touch "${tmpdir}/${sid}.ok"
     ) &
     pids+=($!)
 done
@@ -87,12 +87,19 @@ done
 # Step 3: Wait for all workers.
 for pid in "${pids[@]}"; do wait "$pid" || true; done
 
-# Step 4: Gather results.
+# Step 4: Gather results with status annotations.
 results=""
+failures=0
 for sid in "${workers[@]}"; do
+    if [ -f "${tmpdir}/${sid}.ok" ]; then
+        status="done"
+    else
+        status="failed"
+        failures=$((failures + 1))
+    fi
     out=$(cat "${tmpdir}/${sid}.out" 2>/dev/null || echo "(no output)")
     results="${results}
---- ${sid} ---
+--- ${sid} [STATUS: ${status}] ---
 ${out}
 "
 done
@@ -100,13 +107,15 @@ done
 # Step 5: Synthesize or just print results.
 if [ "$synthesize" -eq 0 ]; then
     printf '%s\n' "$results"
+    [ "$failures" -gt 0 ] && exit 1
 else
     "$B" -backend "$PB" -model "$PM" \
-        "Synthesize these worker results into a final, coherent answer to the original task.
+        "Synthesize these worker results into a final, coherent answer to the original task. Note: workers marked [STATUS: failed] did not complete successfully — account for this in your synthesis.
 
 ORIGINAL TASK:
 $task
 
 WORKER RESULTS:
 $results"
+    [ "$failures" -gt 0 ] && exit 1
 fi