Marks one or more training content items as archived. Archived items are hidden from learners but the records are not permanently deleted.

Returns 200 OK with a success array of archived identifiers and an errors array for any identifiers that could not be found.

Before using this endpoint:

• Training content items must already exist — use the `externalIdentifier` values from the create step.
• Archiving is non-destructive — archived content is hidden from learners but can be restored if needed.
• Unknown identifiers are not treated as a fatal error; they are reported in the `errors` array.

Testing notes: Open the Examples panel and select a Request Example to inspect the body parameters.