Missing input validation for requestTimeout. The parseInt call could result in NaN for invalid input (e.g., --requestTimeout=abc), and negative values aren't validated. Consider adding validation similar to:

if (values.requestTimeout && typeof values.requestTimeout === 'string') {
  const timeout = parseInt(values.requestTimeout);
  if (isNaN(timeout) || timeout < 0) {
    logger.error('requestTimeout must be a non-negative number');
    process.exit(1);
  }
  requestTimeout = timeout;
}

This would provide clear error messages to users who provide invalid timeout values.

Same validation issue as line 352. Missing input validation for requestTimeout. Add validation to check for NaN and negative values before passing to createProcessInstance.

Missing validation: requestTimeout should only be allowed when awaitCompletion is true. The help text states "use with --awaitCompletion" for the requestTimeout flag, but there's no validation enforcing this constraint.

Consider adding validation similar to the fetchVariables check on lines 136-139:

// Validate: requestTimeout requires awaitCompletion
if (options.requestTimeout !== undefined && !options.awaitCompletion) {
  logger.error('--requestTimeout can only be used with --awaitCompletion');
  process.exit(1);
}

This would provide clear feedback to users and prevent confusion when requestTimeout is used without awaitCompletion (where it would have no effect).

The docker-compose infrastructure changes appear to be unrelated to the --requestTimeout feature. This PR should focus on adding the requestTimeout flag. Infrastructure simplifications (switching 8.9 to H2, hardcoding elasticsearch for 8.8, etc.) should be in a separate PR for easier review and to maintain clear commit history per the coding guidelines.

Missing integration test coverage for the --requestTimeout flag. Per the coding guidelines (CodingGuidelineID: 1000000), "for every implementation, make sure to add or update tests that cover the new functionality. This includes unit tests for individual functions and integration tests for end-to-end scenarios."

There should be integration tests that verify:

1. The requestTimeout parameter is correctly passed to the API when using create pi --awaitCompletion --requestTimeout=<ms>
2. The requestTimeout parameter is correctly passed when using await pi --requestTimeout=<ms>
3. The timeout value is properly parsed from the command line (e.g., testing with a valid timeout value)

These tests should be added to tests/integration/process-instances.test.ts following the existing patterns for awaitCompletion tests.