Addresses three reports from issue #196:
- Ping now sends 2 probes with a ~2s timeout (was 1 probe / 1s) so a
single dropped packet or a slow IoT/ESPHome device no longer flaps a
node offline (#196.1, #196.2).
- IPv6-only devices (e.g. Alexa) are now pinged over IPv6: ping6 on
macOS, -6 flag on Linux/Windows, detected via inet_pton (#196.3).
- Manually-added services carry no category and so always rendered grey
even when they were reachable HTTP/HTTPS. A resolvable web URL now
falls back to the web colour (#196.9).
ha-relevant: yes
Pouzor
aa0a97c245