Hubzilla in the pasture

Hubzilla 11.4.1 with its pubcrawl addon (peers/hubzilla.sh): the hlhd image on the shared MySQL, a cron sidecar, hzuser
and hzfriend made through Hubzilla's own PHP as public channels that speak ActivityPub. scenarios/hubzilla.sh, 20
checks: follows, posts, comments, likes, edits and deletions both ways, and a third channel's comment that the thread's
owner passes on, which PrivaPub takes on its FEP-8b32 proof. Known gap G-0010 (upstream): Hubzilla 11 keeps a follower
after its Undo{Follow}.

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

docs/INTEROP.md

@@ -854,6 +854,27 @@ without a port, before it gives out its OAuth client.
   never as the relay's boost), and nobody's home; a persona's public post goes to the relays, nothing less public, and
   reaches Mastodon through both (forwarded on its proof, and announced).
 
+### Hubzilla 11.4.1 (pubcrawl)
+
+- **Channels speak ActivityPub only with the "Activitypub Protocol" app** installed for them (the pubcrawl addon on
+  the hub first). Accounts on Hubzilla 11 come only from its registration queue; the pasture writes the account row as
+  that would (salt, `whirlpool(salt . password)`).
+- **A channel's role decides what its connections may do.** Hubzilla 11 grants what a role's `perms_connect` lists only
+  for the roles `public`, `personal`, `group` and `custom`; the older names its role list still shows (`social`,
+  `social_restricted`, ...) grant a new connection nothing, so it drops everything that connection sends ("store: no
+  permission") while answering 200.
+- **Threads are its owner's:** a comment by another channel in a thread goes to the owner, who passes it on to the
+  thread's audience as the commenter's own Create, with the commenter's FEP-8b32 proof, and adds each activity to the
+  thread's `context` (FEP-171b, `Add{Create}`). PrivaPub takes the forwarded Create on its proof; the `Add` is dropped,
+  the Create having said it already.
+- **Signs everything with a proof** (FEP-8b32) and verifies HTTP signatures; NodeInfo comes from its `statistics`
+  addon.
+- **An unfollow changes nothing there** (G-0010): `Activity::unfollow` deletes the setting `system.their_perms`, which
+  Hubzilla 11 keeps one permission per row under `their_perms`, so the follower stays.
+- **Pasture evidence (2026-10-06, `tools/pasture/scenarios/hubzilla.sh`):** 20 checks pass and one gap is expected
+  (G-0010): follows both ways, posts both ways, comments both ways, a third channel's comment passed on by the thread's
+  owner, likes both ways, edits and deletions both ways, statistics.
+
 ### Smithereen 1.0.3
 
 - **Walls:** a post is a `Note`; one written on someone else's wall carries the wall (`sm:wall`, FEP-400e) as its