Central v1.4 docs

- [ ] Even after a Form is purged, it will still be possible to view all past actions taken on the Form and its Submissions in the Server Audit Log. Those Audit Log entries may record information like the Form ID, the Form title, the Project name, a Submission instance ID, a Submission Attachment filename, and so on. Users should not use sensitive information for those values.

No file, test, or entry point is identified. Locate the Central v1.4 documentation section and review the guidance around purged Forms, Submissions, and the Server Audit Log. Done means the documentation clearly explains that audit entries remain visible and lists the sensitive values users should avoid.

Written by the indexing model from the issue text.