fix(shell): remove wake validation pipe hazards

packages/mosaic/framework/tools/wake/validate-973/validate-973.sh

@@ -107,7 +107,7 @@ if cmp -s "$TMP/expected.txt" "$TMP/static.txt"; then
   echo "STATIC-INVENTORY equals expected set ($(grep -c . "$TMP/static.txt") rows from source text)"
 else
   flag "static inventory (source text) differs from expected set (artifact):"
-  diff "$TMP/expected.txt" "$TMP/static.txt" | head -n 20 | sed 's/^/  /'
+  diff "$TMP/expected.txt" "$TMP/static.txt" | sed -n '1,20p' | sed 's/^/  /'
 fi
 
 # --- 3: green instrumented run ----------------------------------------------
@@ -116,7 +116,7 @@ LEDGER="$TMP/ledger"
 for s in "${SUITES[@]}"; do
   out="$(WAKE_ASSERT_LEDGER="$LEDGER" bash "$WAKE/$s" 2>&1)"
   rc=$?
-  if printf '%s\n' "$out" | grep -Eq "$(sentinel_for "$s")"; then
+  if grep -Eq "$(sentinel_for "$s")" <<<"$out"; then
     sent="present"
   else
     sent="ABSENT"
@@ -177,14 +177,14 @@ while read -r helper site form; do
   rc=$?
   bad=""
   [ "$rc" -ne 0 ] || bad="$bad exit=0"
-  printf '%s\n' "$out" | grep -q "WAKE-ASSERT ARMED: forcing real grep error at $site" ||
+  grep -q "WAKE-ASSERT ARMED: forcing real grep error at $site"  <<<"$out"||
     bad="$bad no-ARMED-line"
-  printf '%s\n' "$out" | grep -q "WAKE-ASSERT ABORT: ${helper} at ${site}: grep exit" ||
+  grep -q "WAKE-ASSERT ABORT: ${helper} at ${site}: grep exit"  <<<"$out"||
     bad="$bad no-ABORT-line"
   # AND-polarity check (a match is the defect): a grep error (rc>=2) must be
   # its own loud arm — it cannot fall through as "no sentinel = pass".
   rc_sent=0
-  printf '%s\n' "$out" | grep -Eq "$(sentinel_for "$f")" || rc_sent=$?
+  grep -Eq "$(sentinel_for "$f")"  <<<"$out"|| rc_sent=$?
   case "$rc_sent" in
   0) bad="$bad sentinel-emitted" ;;
   1) : ;;