fix(keepalive): launchd 环境补 homebrew PATH,修复 node not found

launchd 最小 PATH 不含 /opt/homebrew/bin,keepalive 每小时触发但 4 次全部
exit 127(node: command not found)。对齐 run-web.sh 的 PATH 导出后,
launchctl kickstart 实测:访问成功、无墙、实例正常回收。

bin/keepalive.sh

@@ -7,6 +7,8 @@ set -uo pipefail
 HERE="$(cd "$(dirname "$0")" && pwd)"
 # shellcheck source=platform.sh
 source "$HERE/platform.sh"
+# launchd 环境无 homebrew PATH(node/npx 都在 /opt/homebrew/bin),必须补齐
+export PATH="/opt/homebrew/bin:/usr/local/bin:$PATH"
 
 SITE="${1:-}"
 [ -n "$SITE" ] || { echo "用法: $0 <site>(如 reuters)"; exit 1; }