fix: Disabled Policy Rule P3b Still Active in Code

[Tomeshwari-02]

Summary

This PR fixes the mismatch reported in #249, where delivery slot duration validation was marked as disabled in comments but still executed in policy code.

What changed

• Added a configuration toggle in specification/policies/p2p-trading-interdiscom.rego:
  • data.config.validateDeliverySlotDuration
• Set default behavior to disabled:
  • validateDeliverySlotDuration = false
• Gated both duration rules behind this toggle:
  • Order-side duration check (O3 mirror)
  • Publish-side duration check (P3b mirror)

Tests added

Updated specification/policies/p2p-trading-interdiscom_test.rego with regression tests to verify:

• non-1-hour order duration does not fail when config is unset/default
• non-1-hour publish duration does not fail when config is unset/default
• both checks do fail when validateDeliverySlotDuration: true

Why this change

The policy comments explicitly state P3b is disabled, but the previous implementation still enforced exact 1-hour duration. This PR aligns runtime behavior with documented intent while preserving a safe path to re-enable strict validation via config.

Backward compatibility

• Default behavior changes: exact 1-hour slot validation is now off unless explicitly enabled.
• To restore prior strict behavior, set:

config:
  validateDeliverySlotDuration: true

[ameetdesh]

Suggest closing this PR, because the issue it is based on is not a real issue, but a stale typo in comment. That has since been fixed.