fix: update timeout error message to allow zero

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: bundolee

java/opendataloader-pdf-cli/src/main/java/org/opendataloader/pdf/cli/CLIOptions.java

@@ -500,7 +500,7 @@ private static void applyHybridOptions(Config config, CommandLine commandLine) {
                     config.getHybridConfig().setTimeoutMs(timeout);
                 } catch (NumberFormatException e) {
                     throw new IllegalArgumentException(
-                            String.format("Invalid timeout value '%s'. Must be a positive integer.", timeoutValue));
+                            String.format("Invalid timeout value '%s'. Must be a non-negative integer.", timeoutValue));
                 }
             }
         }