Pull validator out of legal-api

### Replace_With_Short_Descriptive_Name
## Description:
- pull the validator in the legal-api out into it's own library

**Dependencies**

**Acceptance Criteria**

**Validation Rules**

Sprint level Definition of Ready
- [ ] Do we have a prioritized Sprint backlog?
- [ ] Defects, user stories and other work the team has committed to are contained in the sprint backlog?
- [ ] Any hidden work?
- [ ] All team members availability & capacity is known for the sprint?
- [ ] All users stories meet the definition of Ready?

Definition of Ready:
- [ ] Have Stakeholders approved this story?
- [ ] Does User story have full flow of business rules, happy and alternate paths etc. ?
- [ ] Are the dependies known/understood?
- [ ] Dev team accepts user experience artifacts?
- [ ] Are the validation rules defined? (UI, Data, Role-Action)
- [ ] Is a formal UAT required for this user story?
- [ ] Are the acceptance criteria well defined in this ticket (Story level) that QA can confirm or deny ?
- [ ] Does user story need to reference BA checklist? ( are functional/Non functional descriptions captured ?)
- [ ] Is the person who accepts this user story as complete identified? (PO)
- [ ] Can this User story be sized by the Dev. team ?
- [ ] Can this User story be demoed to show value?
- [ ] Is this user story small enough to be completed in a sprint?

Definition of Done:
- [ ] PR to remove feature flags created
- [ ] Check Requirements against completed stories
- [ ] Completed stories verified in Dev/Test/Prod
- [ ] Confirm Test cases built and succeeding
- [ ] Confirm successful End-End runs
- [ ] No regression
- [ ] All Linters passed
- [ ] Test coverage and Test ID acceptable by Product owner
- [ ] Ticket merged to master or story branch
- [ ] Add / maintain selectors for QA purposes
- [ ] Add PR numbers - If available
- [ ] All tests passed (Jest, Pytest, Postman)
- [ ] Developer to list Config changes/ Update documents and designs
- [ ] Design / Solution accepted by Product Owner
- [ ] Acceptance criteria has been defined (happy path, known sad paths)
- [ ] Test coverage acceptable
- [ ] Peer Reviewed
- [ ] Accessibility reviewed and acceptable [checklist](https://github.com/bcgov/entity/docs/coding-standards/accessibility.md)
- [ ] UX Approved
- [ ] PR Accepted
- [ ] Production burn in completed
- [ ] Integration testing completed

The issue only identifies the validator in legal-api and does not name files, tests, dependencies, or extraction boundaries. Start by locating the validator and its callers in legal-api, then clarify the target library interface, validation coverage, and acceptance criteria before attempting the refactor.

Written by the indexing model from the issue text.