network: read the documented host key for the mdns config

mdns_config() documents {host, ...} but maybe_start_mdns read the
`hostname` key, so a spec-conforming config handed mdns:init an
undefined hostname and it crashed on iolist_to_binary/1. Accept both,
preferring the documented key.

Signed-off-by: Paul Guyot <pguyot@kallisys.net>

Author: pguyot

CHANGELOG.md

@@ -82,6 +82,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fixed ESP32 socket driver holding the global socket-list lock across blocking TCP connects, leaking the port on connect failure, losing concurrent `accept` waiters, leaking `netbuf` on receive error paths, and a recycled-`netconn` race between socket close and the event handler
 - Fixed generic_unix TCP server sockets performing an abortive close that could truncate replies awaiting ack
 - Fixed a JIT crash (`EXC_BAD_ACCESS`/SIGBUS) on Apple Silicon
+- Fixed the `network` mdns configuration to read the documented `host` key; the previously
+  required, undocumented `hostname` key is still accepted
 
 ## [0.7.0-alpha.1] - 2026-04-06
 

libs/avm_network/src/network.erl

@@ -988,8 +988,15 @@ maybe_start_mdns(#state{config = Config, sta_ip_info = {InterfaceAddr, _, _}} =
         undefined ->
             State;
         MDNSConfig ->
+            % The documented config key is `host` (see mdns_hostname_config());
+            % `hostname` is accepted too for compatibility with older code.
+            Hostname =
+                case proplists:get_value(host, MDNSConfig) of
+                    undefined -> proplists:get_value(hostname, MDNSConfig);
+                    Host -> Host
+                end,
             MDNSMap0 = #{
-                hostname => proplists:get_value(hostname, MDNSConfig), interface => InterfaceAddr
+                hostname => Hostname, interface => InterfaceAddr
             },
             MDNSMap1 =
                 case proplists:get_value(ttl, MDNSConfig) of