F4.16 Device list updates #355

Spec: docs/features/F4.16-device-list.md (decisions agreed 2026-10-19). Unblocked by APRS.NET 0.5.0-alpha.2, which delivers G35 (AprsDeviceList, AprsDeviceListSource).

What it does:

• Fetch the aprs-deviceid list weekly, or on demand with Update now, from the APRS Foundation or a mirror.
• Use whichever list is newer, the downloaded one or the one built into APRS.NET.
• When the list changes, identify already-heard stations again.

Where it shows:

• Settings › Data shows the list in use, the last check, Update now and the schedule.
• About credits the list (CC BY-SA 2.0).
• On a gateway, Update now and the schedule are the operator's.

Nothing is fetched while the Internet switch is off.