Fix federation for comments on cached ActivityPub posts

[akirk]

Summary

• Mark cached ActivityPub-capable Friends posts as federated before ActivityPub evaluates newly inserted local comments.
• Allows local replies on cached remote ActivityPub posts to enter the ActivityPub outbox.
• Update the regression test so it starts without pre-seeded activitypub_status metadata, matching the production failure case.

Test plan

• composer test -- --filter ActivityPubTest::test_comment_on_cached_post_federation
• composer check-cs
• Confirmed repaired comment 88645 reached the Mastodon status thread.

Test in WordPress Playground

Changelog

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Type

• Fixed

Message

Fix local replies on cached ActivityPub posts not entering the outbox.