Implement target selection, autodiscovery via aggregator, implement listTargets

cmd/cli/main.go

@@ -11,6 +11,7 @@ Usage:
   logtail-cli topn    [flags]   ranked label → count list
   logtail-cli trend   [flags]   per-minute time series
   logtail-cli stream  [flags]   live snapshot feed
+  logtail-cli targets [flags]   list targets known to the queried endpoint
 
 Subcommand flags (all subcommands):
   --target  host:port[,host:port,...]  endpoints to query (default: localhost:9090)
@@ -43,6 +44,8 @@ func main() {
 		runTrend(os.Args[2:])
 	case "stream":
 		runStream(os.Args[2:])
+	case "targets":
+		runTargets(os.Args[2:])
 	case "-h", "--help", "help":
 		fmt.Print(usage)
 	default: