Removed a duplicate computation of body's filehash

[jamesbraza]

We used to always compute the filehash twice, now it's just once.

[Copilot]

Pull Request Overview

This PR eliminates duplicate computation of filehash for document bodies by passing the computed hash value between methods instead of recomputing it.

• Modified filecheck method to accept a pre-computed filehash instead of the body string
• Removed redundant filehash computation in the add_document method
• Updated variable naming from filehash to body_filehash for clarity

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[dosubot]

Documentation updates
Checked 1 published document(s). No updates required.

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