Starlink's USB ethernet shares a hub with the rtw89 Wi-Fi adapter; when Starlink
flaps, the hub re-enumerates and tears the radio down, so hostapd loses its
interface and exits. Two stock defaults left the AP dark: Restart=on-failure
misses clean exits, and the 5-in-10s start limit makes systemd give up during a
re-enumeration storm.
- hostapd-restart.conf drop-in: Restart=always, RestartSec=5, StartLimitIntervalSec=0
so hostapd retries forever until the interface returns (verified: SIGKILL -> back
to state=ENABLED in ~7s).
- van-ap-watchdog daemon: backstop for the case systemd can't see (hostapd running
but radio wedged). Polls hostapd_cli status; restarts hostapd if the iface is
present but not ENABLED, waits it out if the iface is mid-re-enumeration.
- hostapd.conf: add ctrl_interface so the watchdog can read the real AP state.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
