Following an account brings its earlier posts to its profile

Once a follow holds, OutboxBackfill reads the account's latest public posts from its outbox's first page (twenty at
most, once a day) and keeps them as any fetched post: its profile shows them at once instead of only what it posts from
then on. Homes still get only what arrives afterwards, as on Mastodon. Announces and other servers' objects in the
outbox are left out. Checked live against Mastodon (scenarios/pins.sh, now 9 checks).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw

CLAUDE.md

@@ -560,7 +560,8 @@ tools/pasture/run.sh down                                            # removes e
   only as `ChatMessage`, which PrivaPub sends it, a first message too (invariant 17). `scenarios/lemmy19.sh`, 30
   checks.
 - **Pins (`scenarios/pins.sh`, needs mastodon):** a Mastodon account pins and unpins while alice follows it, alice pins
-  and unpins while it follows her, and a fresh account's earlier pin shows once PrivaPub resolves it. 8 checks.
+  and unpins while it follows her, a fresh account's earlier pin shows once PrivaPub resolves it, and following it brings
+  its earlier posts (its outbox). 9 checks.
 - **Vernissage (1.43.0):** its image on SQLite in the `pasture-vernissage` volume, its queues on the shared Redis's
   database 0 (it federates nothing without them; every other database is taken), its seeded admin (admin / admin)
   logged in by the scenario. `scenarios/vernissage.sh`, 19 checks.