hosts/van.conf: record the R5C's current dongles; tests read host values

The R5C's 2.4GHz AP now uses the D-Link dongle wlxf4f26d1760a7 (the same
dongle hosts/wan.conf lists — it moves between hosts) and a Wi-Fi WAN test
dongle wlx200bd04dc756 is configured (not always attached; van-failover
treats an absent device as "not present").

The tests no longer hardcode this host's hardware: assertions read the
expected interface names from the host file (hv helper), and the "no Wi-Fi
WAN" path (no wifis: stanza, `wifi WAN: none`) is covered with a synthetic
copy of van.conf with WIFI_WAN_IFACE emptied.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KqhjP7nud5gdBg25zCiRk9

hosts/van.conf

@@ -2,10 +2,10 @@
 # /etc/vanlink.conf -> this file. See hosts/vanlink.conf.example for the variable list.
 
 WIFI_5G_IFACE=wlp1s0            # MediaTek MT7925E (PCIe); 2.4GHz AP is the separate USB dongle below
-WIFI_2G_IFACE=wlx3c3332002066   # D-Link USB dongle
+WIFI_2G_IFACE=wlxf4f26d1760a7   # D-Link USB dongle (2.4GHz AP; the same dongle is listed in hosts/wan.conf — it moves between the hosts)
 LAN_IFACE=enP1p17s0
 STARLINK_IFACE=enP2p33s0
-WIFI_WAN_IFACE=                 # none: no spare radio (the R5C's two radios are both APs)
+WIFI_WAN_IFACE=wlx200bd04dc756   # Wi-Fi uplink test dongle (RTL8821CU); not always attached — van-failover treats an absent device as "not present"
 ONBOARD_LAN_IFACE=
 
 GATEWAY_IP="10.42.1.1"
@@ -34,12 +34,13 @@ ENABLE_NVME_WATCH=0             # no NVMe on this board
 ENABLE_HA=1
 ENABLE_FRIGATE=1
 ENABLE_NM_WAN=1
-ENABLE_LEDS=1                   # R5C front LEDs (van-leds)
 
+CELLULAR_CONN_NAME=Koodo
+CELLULAR_APN=sp.koodo.com
+
+# Front LEDs
+ENABLE_LEDS=1                   # R5C front LEDs (van-leds)
 LED_POWER=red:power
 LED_LAN=green:lan
 LED_WAN=green:wan
 LED_WLAN=green:wlan
-
-CELLULAR_CONN_NAME=Koodo
-CELLULAR_APN=sp.koodo.com