Upgrade ActivityPub container to v1.2.0 when released

[noahwhite]

Context

Ghost Admin's Network section (Profile and Explore pages) returns "Oops, page not found" because Ghost 6.21 ships an ActivityPub frontend client requiring API v3.x, which depends on the /v1/recommendations endpoint. This endpoint was added to TryGhost/ActivityPub in PR #1462 (merged 2025-12-08), four months after the v1.1.0 tag (2025-08-08).

As of 2026-03-13, no v1.2.0 tag exists on GHCR. Renovate will automatically open a PR when a new image is published.

Acceptance Criteria

• ghcr.io/tryghost/activitypub and ghcr.io/tryghost/activitypub-migrations are upgraded to the new version in compose.yml.tftpl
• Ghost Admin Network → Profile loads without "Oops, page not found"
• Ghost Admin Network → Explore loads without error
• Deploy completes successfully and health check passes

References

• TryGhost/ActivityPub PR #1462: Added recommendations endpoint for sidebar/in-feed recs TryGhost/ActivityPub#1462
• TryGhost/ActivityPub PR #1467 (versioning context): Updated client config with new major (3.x) TryGhost/ActivityPub#1467

[linear]

GHO-107