node/endpoint.rs (probe_mdns_socket) detects when UDP 5353 is blocked - the #1 reason LAN discovery silently fails - but only logs it. Surface the probe result in the Diagnostics view (src/components/SettingsView.tsx diagnostics section) with the firewall hint text.
Acceptance: probe result travels through get_network_diagnostics; UI shows a clear warning card when blocked.
node/endpoint.rs(probe_mdns_socket) detects when UDP 5353 is blocked - the #1 reason LAN discovery silently fails - but only logs it. Surface the probe result in the Diagnostics view (src/components/SettingsView.tsx diagnostics section) with the firewall hint text.Acceptance: probe result travels through get_network_diagnostics; UI shows a clear warning card when blocked.