[Testing] Enhance local runner validation

Migration from https://github.com/aws/aws-durable-execution-sdk-python-testing/issues/26

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## Context
Implement backend service worker validation rules in local runner

## Technical Requirements
- Implement backend service worker validation rules in local runner
- Add corresponding exception handling for new validation errors
- Update existing tests to handle new validation logic

## Acceptance Criteria
- [ ] Backend service worker validation rules implemented in local runner
- [ ] Exception handling added for new validation errors
- [ ] Existing tests updated to handle new validation logic

Start by locating the local runner implementation and its existing validation tests, then trace how backend service-worker errors are currently handled. Implement the stated validation and exception behavior, update the existing tests for the new logic, and confirm the test suite passes.

Written by the indexing model from the issue text.