Improve phaseflow-cron logging on failure

Show the API response body in logs instead of silently failing
with curl exit code 22.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

services/phaseflow-cron.hcl

@@ -24,9 +24,19 @@ job "phaseflow-cron" {
         destination = "local/script.sh"
         data        = <<EOH
 set -e
-/run/current-system/sw/bin/curl -s -f -X POST \
+RESPONSE=$(/run/current-system/sw/bin/curl -s -w "\n%%{http_code}" -X POST \
   -H "Authorization: Bearer $CRON_SECRET" \
-  https://phaseflow.v.paler.net/api/cron/garmin-sync
+  https://phaseflow.v.paler.net/api/cron/garmin-sync)
+
+HTTP_CODE=$(echo "$RESPONSE" | tail -n1)
+BODY=$(echo "$RESPONSE" | sed '$d')
+
+echo "$BODY"
+
+if [ "$HTTP_CODE" -ge 400 ]; then
+  echo "HTTP error: $HTTP_CODE" >&2
+  exit 1
+fi
 EOH
       }