[plan] Fix schema consistency issues from implicit validation audit

[github-actions]

Overview

This tracking issue addresses schema consistency problems discovered during an implicit constraints and validation rules audit. The audit found 3 inconsistencies where code behavior differs from schema specifications.

Source: Discussion #6199

Key Findings

• Critical: PR review comments default value mismatch (schema says 1, code implements 10)
• Moderate: Missing engine.transports field in schema
• Low: Time delta maximum bounds not documented in schema

Planned Tasks

This work is broken down into focused sub-issues:

1. Fix PR review comments default value mismatch (critical)
2. Add engine.transports field to schema definition
3. Document time delta maximum values in schema
4. Add schema-code consistency tests to prevent future drift

Success Criteria

• Schema documentation matches code implementation
• All fields referenced in code are defined in schema
• Validation constraints are documented
• Automated tests catch future inconsistencies

AI generated by Plan Command for discussion #6199