ap: parallel 2.4GHz AP (hostapd-2g) on the Linksys WUSB6300v2 dongle

Second radio (wlxd8ec5e2faa8c, RTL8822BU/rtw88), same VanLink SSID+PSK,
ch6 HT20, bridged into br0 next to the 5GHz AP. Runs as its own hostapd
instance + own watchdog so a USB wedge on one radio never darkens the
other; van-ap-watchdog now takes conf path + unit name as args (defaults
unchanged). rtw88.conf disables deep power-save (rtw89 gotcha analog)
and the driver's USB2->3 self-upgrade (USB3 noise in the 2.4GHz band —
note: dongle currently sits in a USB3 port, so it still enumerates
SuperSpeed; move to a USB2 port if 2.4GHz range disappoints).

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

ap/11-van-ap-2g.network

@@ -0,0 +1,11 @@
+[Match]
+Name=wlxd8ec5e2faa8c
+
+[Link]
+RequiredForOnline=no
+
+# No IP here: like the 5GHz AP wlan (10-van-ap.network), this is a br0 member —
+# hostapd-2g adds it to the bridge after putting the radio into AP mode. networkd
+# must NOT enslave it; this file only brings the link up.
+[Network]
+ConfigureWithoutCarrier=yes