Add status progress for batch tool operations

standalone/json.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"encoding/json"
+	"fmt"
 	"net/http"
 )
 
@@ -9,3 +10,27 @@ func writeJSON(w http.ResponseWriter, v any) {
 	w.Header().Set("Content-Type", "application/json")
 	_ = json.NewEncoder(w).Encode(v)
 }
+
+func newJSONStream(w http.ResponseWriter) func(any) {
+	w.Header().Set("Content-Type", "application/x-ndjson; charset=utf-8")
+	w.Header().Set("Cache-Control", "no-cache")
+	flusher, _ := w.(http.Flusher)
+	return func(v any) {
+		data, err := json.Marshal(v)
+		if err != nil {
+			data = []byte(fmt.Sprintf(`{"type":"error","message":%q}`, err.Error()))
+		}
+		_, _ = w.Write(data)
+		_, _ = w.Write([]byte("\n"))
+		if flusher != nil {
+			flusher.Flush()
+		}
+	}
+}
+
+func pluralS(n int) string {
+	if n == 1 {
+		return ""
+	}
+	return "s"
+}