fix for draft edit link

[deepikaSingh2711]

Describe your changes

Problem: After saving an entity with a link attachment, the "Edit Link" button didn't appear when editing the entity again.

Fix: Restore correct mimeType for link attachments after save by checking if linkUrl exists and correcting the mimeType.

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist before requesting a review

• I have tested the functionality on my cloud environment.
• I have provided sufficient automated/ unit tests for the code.
• I have increased or maintained the test coverage.
• I have ran integration tests on my cloud environment.
• I have validated blackduck portal for any vulnerability after my commit.

Upload Screenshots/lists of the scenarios tested

• I have Uploaded Screenshots or added lists of the scenarios tested in description

Single tenant Integration test
https://github.com/cap-js/sdm/actions/runs/22898011199

TENANCY_MODEL=multi TENANT=SDM-DEV-CONSUMER-EU12 npm run integration-test

TENANCY_MODEL=multi TENANT=SDMGoogleWorkspaceConsumer npm run integration-test