feat: exclusive pilot — spool flush and verify script

Replay spool on each monitor loop; sac_post_payload refactor;
pilot-verify-exclusive.sh and --check-sac hints for exclusive mode.

scripts/pilot-verify-exclusive.sh

@@ -0,0 +1,41 @@
+#!/bin/bash
+# Проверка готовности хоста к пилоту UseSAC=exclusive (фаза 2.1).
+set -euo pipefail
+
+CONFIG="${CONFIG_FILE:-/etc/ssh-monitor.conf}"
+MONITOR="${SSH_MONITOR_BIN:-/usr/local/bin/ssh-monitor}"
+
+if [ -f "$CONFIG" ]; then
+ # shellcheck disable=SC1090
+ . "$CONFIG"
+fi
+
+fail=0
+ok() { printf '[OK] %s\n' "$1"; }
+bad() { printf '[FAIL] %s\n' "$1"; fail=1; }
+
+mode="$(printf '%s' "${UseSAC:-off}" | tr '[:upper:]' '[:lower:]')"
+[ "$mode" = "exclusive" ] || bad "UseSAC должен быть exclusive (сейчас: ${UseSAC:-off})"
+[ -n "${SAC_URL:-}" ] && [ -n "${SAC_API_KEY:-}" ] || bad "Задайте SAC_URL и SAC_API_KEY"
+[ -x "$MONITOR" ] || bad "Не найден $MONITOR"
+[ -f "${MONITOR%/*}/sac-client.sh" ] || bad "Нет sac-client.sh рядом с ssh-monitor"
+
+if "$MONITOR" --check-sac; then
+ ok "--check-sac"
+else
+ bad "--check-sac"
+fi
+
+spool="${SAC_SPOOL_DIR:-/var/lib/ssh-monitor/sac-spool}"
+pending=0
+if [ -d "$spool" ]; then
+ pending=$(find "$spool" -maxdepth 1 -name '*.json' 2>/dev/null | wc -l)
+fi
+printf '     Spool %s: %s файл(ов)\n' "$spool" "$pending"
+
+if [ "$fail" -eq 0 ]; then
+ printf '\nПилот exclusive: хост готов. Сгенерируйте SSH/sudo событие и проверьте только в SAC UI.\n'
+ exit 0
+fi
+printf '\nИсправьте ошибки выше.\n'
+exit 1