Task: Post-Beta Entry to Wagtail Page Sync

## Goal

Implement a mechanism to sync entries created during the beta period to Wagtail pages after beta ends.

---

## Scope

Backend: entry-to-page sync strategy and implementation.

---

## Background

During the beta period, users on V2 create Entries while users on V3 create Wagtail Pages. Any entries created mid-beta need to be reconciled into Wagtail pages post-beta to prevent missing news items in the feed after launch.

---

## Acceptance Criteria

- All entries created during the beta period are synced to Wagtail pages post-beta.
- The sync is idempotent, running it multiple times does not create duplicate pages.
- Missing or failed entries are logged and surfaced for manual review.
---

## Out of Scope

- V3 legacy news feed removal (already completed)
---

## Notes

- This ticket is being tracked on the launch checklist.
- Unresolved entries at the end of the beta period are a bug risk, missing news items in the feed post-launch.

No files, tests, or entry points are named in the issue. Start by locating the beta-period Entry data and the Wagtail page creation path, then define how to identify all beta entries, make synchronization idempotent, and surface missing or failed entries for review.

Written by the indexing model from the issue text.