Content import leaves contentlets locked when relationship field value is invalid and import fails

Problem Statement

When importing content via csv, if a relationship field column contains an invalid value (e.g. HTML text instead of a valid identifier or Lucene query), the contentlet being referenced gets locked during the "Go To Preview" step — and because the import subsequently fails validation, it never reaches the unlock step. The lock persists indefinitely.

ImportUtil.processRelationships() [line ~2717]
└─▶ RelationshipUtil.getRelatedContentFromQuery() [line 59]
└─▶ filterContentlet(language, query, user, true) ← isCheckout hardcoded TRUE
└─▶ contentletAPI.checkout() ← locks the related contentlet

Steps to Reproduce

https://drive.google.com/file/d/1D6pw9zB0DBxacWFv3HV4pA8R67QjJEVH/view?usp=drive_link

Acceptance Criteria

Expected Behavior

Contentlets should be unlocked automatically when:

The import preview/process fails validation, and
The user clicks "Cancel" on the preview/conflicts screen

dotCMS Version

26.06.04-01

Severity

Medium - Some functionality impacted

Links

https://helpdesk.dotcms.com/a/tickets/37916

Start with ImportUtil.processRelationships() around line 2717 and RelationshipUtil.getRelatedContentFromQuery() around line 59, then trace the preview validation and Cancel flows. Reproduce the CSV import with an invalid relationship value and verify that referenced contentlets are unlocked after validation failure and after Cancel.