admin control features and admin dashboard

internal/dashboard/util.go

@@ -0,0 +1,21 @@
+package dashboard
+
+import "strings"
+
+// splitList parses a textarea/hidden-input value into a clean list,
+// accepting entries separated by newlines and/or commas interchangeably
+// (different forms in this package use one or the other) and dropping
+// blank entries from stray whitespace.
+func splitList(raw string) []string {
+	fields := strings.FieldsFunc(raw, func(r rune) bool {
+		return r == '\n' || r == '\r' || r == ','
+	})
+	out := make([]string, 0, len(fields))
+	for _, f := range fields {
+		f = strings.TrimSpace(f)
+		if f != "" {
+			out = append(out, f)
+		}
+	}
+	return out
+}