Clean up and validate Skull dataset data

🎯 Goal / Objective

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There are some lingering errors in the Skull dataset, such as errors in text labels, descriptions, etc. In particular, many bones do not have description, for example there is no description/skull_description.json, causing the Skull page not to load right.

✅ Tasks to be Completed

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• Run the web app alongside the Skull slideshow and follow along. Fix any discrepancies between the data displayed in the app and what is in the slideshow.

Acceptance Criteria

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• The new feature is implemented as described.
• All related code passes the repository's workflow checks (linting, tests).
• The application runs without errors after the changes are made.
• (If applicable) New automated tests have been added to cover the changes.
• Any related documentation has been updated, including JSDoc comments or docstrings

Additional Context

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[!IMPORTANT]
Though not a strict prerequisite, it may be easier to complete this task if #374 is completed first.

Start by running the web app alongside the Skull slideshow and compare the displayed data with the source data, paying particular attention to the missing description/skull_description.json mentioned in the issue. Correct the identified label, description, and other discrepancies, then verify that the Skull page loads without errors and that the repository workflow checks pass; issue #374 may provide useful prior context.