Add is_tor plumbing from collector->aggregator->frontend/cli

cmd/frontend/filter.go

@@ -113,8 +113,21 @@ func applyTerm(term string, fs *filterState) error {
 			return fmt.Errorf("prefix only supports =, not %q", op)
 		}
 		fs.Prefix = value
+	case "is_tor":
+		if op != "=" && op != "!=" {
+			return fmt.Errorf("is_tor only supports = and !=, not %q", op)
+		}
+		if value != "0" && value != "1" {
+			return fmt.Errorf("is_tor value must be 0 or 1, not %q", value)
+		}
+		// Normalise: is_tor=1 and is_tor!=0 both mean "TOR only"
+		if (op == "=" && value == "1") || (op == "!=" && value == "0") {
+			fs.IsTor = "1"
+		} else {
+			fs.IsTor = "0"
+		}
 	default:
-		return fmt.Errorf("unknown field %q; valid: status, website, uri, prefix", field)
+		return fmt.Errorf("unknown field %q; valid: status, website, uri, prefix, is_tor", field)
 	}
 	return nil
 }
@@ -151,6 +164,9 @@ func FilterExprString(f filterState) string {
 	if f.Status != "" {
 		parts = append(parts, statusTermStr(f.Status))
 	}
+	if f.IsTor != "" {
+		parts = append(parts, "is_tor="+f.IsTor)
+	}
 	return strings.Join(parts, " AND ")
 }