feat(webui): responsive tweaks for mobile; seed channels from config when DB empty; expose KnownChannels on server

cmd/sojuboy/main.go

@@ -122,6 +122,7 @@ func main() {
 		Commit:            commit,
 		BuiltAt:           builtAt,
 		StartedAt:         time.Now(),
+		KnownChannels:     cfg.Channels,
 	}
 	go func() {
 		if err := api.Start(ctx); err != nil && err != http.ErrServerClosed {