Anchored directive validation failing to catch plan bound violations in some cases

[AaronPlave]

Checked for duplicates

Yes - I've already checked

Is this a regression?

No - This is a new bug

Version

2.1.0

Describe the bug

Found this issue when testing https://github.com/NASA-AMMOS/aerie-ui/pull/1066, see https://github.com/NASA-AMMOS/aerie-ui/pull/1066#issuecomment-1870555797 for the original comment.

An anchored directive is not correctly reported as outside of plan time bounds in the following case:

1. Negatively anchor directive A to a plan which should (with https://github.com/NASA-AMMOS/aerie-ui/pull/1066) be reported as out of plan bounds.
2. Anchor directive B to directive A with a positive offset to directive A. Notice that directive B is not reported as out of bounds.
3. Negatively offset directive B to directive A. Notice that directive B will be correctly reported as out of bounds.

Reproduction

See above

Logs

No response

System Info

N/A

Severity

Moderate