Add --dry-run to the weekly health check

Lets the email be read before it is sent, which matters for a message whose whole
job is to be clear at a glance a week from now.

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

scripts/weekly-health.sh

@@ -15,6 +15,11 @@
 
 set -uo pipefail
 
+# --dry-run prints the email instead of sending it. Useful for reading what it will say
+# before a week goes by, and for checking the wording without filling an inbox.
+DRY=0
+[ "${1:-}" = "--dry-run" ] && DRY=1
+
 ROOT="$(cd "$(dirname "$0")/.." && pwd)"
 NAS_HOST="10.1.1.5"
 NAS_USER="Christian"
@@ -122,5 +127,10 @@ $LINES
 MSG
 fi
 
+if [ "$DRY" = 1 ]; then
+  printf 'Subject: %s\n\n' "$SUBJECT"
+  cat "$BODY_FILE"
+else
   node "$ROOT/scripts/alert.js" "$SUBJECT" "$(cat "$BODY_FILE")"
+fi
 rm -f "$BODY_FILE"