feat(iso): auto-queue an Audit task once bee-web is up

Adds bee-autoaudit.service: after the boot-time bee-web/bee-audit/
bee-preflight/bee-network units settle, it waits for bee-web to answer
/healthz and then POSTs to the same /api/audit/run endpoint the "Run Audit"
button uses. An operator opening the web UI right after boot now finds a
completed Audit task (report + charts) waiting instead of an empty task
history. Best-effort: any failure just falls back to the manual button.

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

iso/overlay/etc/systemd/system/bee-autoaudit.service

@@ -0,0 +1,13 @@
+[Unit]
+Description=Bee: automatically queue an Audit task once the web UI is up
+After=bee-web.service bee-audit.service bee-preflight.service bee-network.service
+StartLimitIntervalSec=0
+
+[Service]
+Type=oneshot
+ExecStart=/usr/local/bin/bee-log-run /appdata/bee/export/bee-autoaudit.log /usr/local/bin/bee-autoaudit
+StandardOutput=journal
+StandardError=journal
+
+[Install]
+WantedBy=multi-user.target