T14: Lemmy 1.0 in the pasture

peers/lemmy.sh runs the Lemmy 1.0.0-beta.2 backend on the shared Postgres. It trusts
Caddy's CA through SSL_CERT_FILE and reaches the pasture through
DANGER_FEDERATION_ALLOW_LOCAL_IP. Lemmy 0.19 cannot join: its rustls trusts only its
bundled roots. LEMMY_LOG sets RUST_LOG.

scenarios/lemmy.sh drives Lemmy through its v4 API. 20 checks pass, three runs in a row:
- communities both ways;
- a titled thread each way, and alice's mention of a Lemmy community becoming a thread
  there;
- the Lemmy community's announce reaching alice's home;
- comments both ways and alice's like as an upvote;
- private messages both ways;
- statistics.

Two expected failures: votes, which Lemmy sends only through the community as
Announce{Like|Dislike}, and a moderator's removal. Both belong to P7.

What it showed, in docs/INTEROP.md:
- Lemmy 1.0 keeps its user's thread in a remote community pending until the community
  announces it back. It clears the flag before answering that echo 400 ("Object is not
  remote"). Leaving the author's server out of the Announce, as tried here, left every
  such thread pending, so GroupDistributor now says why the echo stays.
- Every bare Announce{object} is answered 400, as Lemmy answers its own compatibility
  Announce(Page).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ELjqpznMFMNrJoJUj6K5p2

CLAUDE.md

@@ -414,6 +414,13 @@ tools/pasture/run.sh down                                            # removes e
   (`federation: none`) until `admin/update-meta` says `all`, which `misskey_up` does. Its API is `POST /api/<endpoint>`
   with the token as `i` (`mk` in the scenario); `users/relation` answers a list, `users/notes` leaves replies out unless
   asked, and a user has one reaction per note. Never verify a delivery with `ap/show`: it fetches. 35 checks.
+- **Lemmy (1.0.0-beta.2):** the backend alone on the shared Postgres, its admin made by `setup` in the generated
+  `config.hjson`. It trusts Caddy's CA through `SSL_CERT_FILE` and reaches the network through
+  `DANGER_FEDERATION_ALLOW_LOCAL_IP=1`; 0.19 cannot join (its rustls trusts only its bundled roots). Its API is
+  `/api/v4/<path>` with a bearer token (`lm` in the scenario), and `sort` values are lowercase. It logs no refused
+  activity at `warn` (`LEMMY_LOG` sets `RUST_LOG`); the reason is in the 400's body. It answers our community's echo of
+  its own activity and every bare `Announce{object}` 400 by design, and the echo is still needed (see
+  `docs/INTEROP.md`, Lemmy). 20 checks; relayed votes and a moderator's removal are expected failures (P7).
 - **Crawler:** `PRIVAPUB_ENV="Statistics__Crawler__Enabled=true Statistics__Crawler__Seeds__0=mastodon.test"
   run.sh up mastodon`, then `interop.sh crawler`. `PRIVAPUB_ENV` passes any setting to the PrivaPub container.
 - `run.sh up` replaces every container, Mongo included, so each run starts clean. To keep the data, republish into