feat: add broken content fragment links audit type

[holtvogt]

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• make sure to link the related issues in this description
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Related Issues

• feat: add audit for broken content fragment requests spacecat-audit-worker#1282

[Copilot]

Pull Request Overview

This PR adds support for a new audit type BROKEN_CONTENT_FRAGMENT_LINKS to track broken content fragment links. The change includes:

• Adding the new audit type constant to the model
• Updating the test to reflect the increased count of audit types
• Fixing a documentation typo in the README

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
packages/spacecat-shared-data-access/src/models/audit/audit.model.js	Adds the new BROKEN_CONTENT_FRAGMENT_LINKS audit type constant
packages/spacecat-shared-data-access/test/unit/models/audit/audit.model.test.js	Updates test expectations to include the new audit type and increments the total count from 31 to 32
packages/spacecat-shared-splunk-client/README.md	Fixes a typo in the example configuration code (removes extra > character)

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[github-actions]

This PR will trigger a patch release when merged.