Update Employee File

Updates metadata for an existing employee file. Supports renaming the file, moving it to a different category, and toggling employee visibility. Accepts JSON or XML; only fields present in the request body are updated. An empty XML document no-ops successfully, while an empty JSON body returns 400. The categoryId field is silently ignored when the caller authenticated as the file creator but lacks full file permissions. Moving a file to a new category requires view/edit access to both the current and target category. Returns 403 if the file belongs to a read-only file section. Use 'List Employee Files' to obtain file IDs and category IDs.

OAuth Scopes: employee:file.write