fix(13-09): verify-aiui-deploy false-negative — pipefail EPIPEs curl on grep -q early exit

curl | grep -q under set -o pipefail: grep's first-match exit EPIPEs curl
(exit 23) whenever the marker precedes the tail of a >64KB chunk, so a
genuine deploy read as FAIL (bit during 13-08's AIUI redeploy — marker at
27% of a 416KB chunk failed 3/3 runs). Fetch to a temp file, then grep.
Negative control still fails as it should.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

scripts/verify-aiui-deploy.sh

@@ -63,11 +63,17 @@ echo "$(timestamp) Resolved ${#LIVE_PATHS[@]} live chunk(s) from the precache ma
 
 FOUND=0
 CHECKED=0
+# Fetch to a temp file and grep that, NOT `curl | grep -q`: under this
+# script's pipefail, grep -q's early exit EPIPEs curl (exit 23) whenever
+# the marker sits before the tail of a >64KB chunk, turning a genuine
+# match into a nondeterministic FAIL.
+BODY_TMP="$(mktemp)"
+trap 'rm -f "$BODY_TMP"' EXIT
 for path in "${LIVE_PATHS[@]}"; do
     [ -z "$path" ] && continue
     CHECKED=$((CHECKED + 1))
     url="${BASE}/aiui/${path}"
-    if curl -sf -m 15 "$url" 2>/dev/null | grep -q -- "$MARKER"; then
+    if curl -sf -m 15 -o "$BODY_TMP" "$url" 2>/dev/null && grep -q -- "$MARKER" "$BODY_TMP"; then
         echo "$(timestamp)   MATCH: $path"
         FOUND=1
         break