Add created date to context item entity

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Update Summary: Add created date to context item entity
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Problem/Motivation

Follow-up to:

📌 Update context item edit form to better align with core Active

The created property wasn't available when working on that issue, and I didn't have enough time to add it there.

Add the created property and then ideally update the sidebar to show it like to how the node edit form shows it.

Proposed resolution

Add created

Target date or deadline

Remaining tasks

• Update code
• Review and test
• Merge