fix: only the owner decides who hosts a group, and nobody is made a member unasked

- hub: a node may host a group only if its account owns it or the owner
  approved that node (new `group_hosts`). Membership was the ceiling, and
  every member holds the group key, so any member's node could register as a
  host and be the one clients kept. A node claiming a group it may not host
  is recorded as a request; the owner is notified once and approves or
  refuses it (GET/POST/DELETE /v1/groups/{id}/hosts[/{node_id}]), which
  takes effect on a connected node at once.
- hub: an owner adding a username creates an invitation (new
  `group_invitations`), accepted or declined by the invitee
  (/v1/groups/invitations, /{id}/invitation/accept|decline). Until then the
  group is not listed, not dialled, not searched and not in any token.
  Invitation links, open joins and group creation still make members
  directly: they are the account's own act.
- hub: the MNP token names only the group it is minted for (group_id is now
  required), so a node operator no longer learns a member's other groups.
- SPA: invitations on the home page; invited people and host requests in
  the group's settings; the transport sends group_id. Ten catalogues.
- Browser probes for both screens, run in Chrome and Firefox.
- Design §5.2, §7.2, §7.3, AV32, AV33; protocol §6.3; user guide.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 4 insertions, 6 deletions

diff --git a/packages/meshbay-hub/tests/test_notifications_behaviour.py b/packages/meshbay-hub/tests/test_notifications_behaviour.py
index 4684d3f..2d0b273 100644
--- a/packages/meshbay-hub/tests/test_notifications_behaviour.py
+++ b/packages/meshbay-hub/tests/test_notifications_behaviour.py
@@ -11,6 +11,7 @@ import base64
 import hashlib
 
 import pytest
+from membership import add_member
 from meshbay_hub.db.models import GroupMember, Notification, User
 from sqlalchemy import select
 
@@ -40,8 +41,7 @@ async def test_chat_keeps_one_notification_per_group(client, db_session):
     g = await client.post("/v1/groups", json={"name": "busy"},
                           headers={"Authorization": f"Bearer {owner}"})
     gid = g.json()["group_id"]
-    await client.post(f"/v1/groups/{gid}/members/listener", json={},
-                      headers={"Authorization": f"Bearer {owner}"})
+    await add_member(client, gid, 'listener', {"Authorization": f"Bearer {owner}"})
     uid = (await db_session.execute(
         select(User.id).where(User.username == "listener"))).scalar_one()
 
@@ -72,8 +72,7 @@ async def test_muting_a_group_stops_notifications_being_created(client, db_sessi
     g = await client.post("/v1/groups", json={"name": "loud"},
                           headers={"Authorization": f"Bearer {owner}"})
     gid = g.json()["group_id"]
-    await client.post(f"/v1/groups/{gid}/members/quiet_test", json={},
-                      headers={"Authorization": f"Bearer {owner}"})
+    await add_member(client, gid, 'quiet_test', {"Authorization": f"Bearer {owner}"})
 
     r = await client.post(f"/v1/groups/{gid}/mute", json={"muted": True},
                           headers={"Authorization": f"Bearer {token}"})
@@ -170,8 +169,7 @@ async def test_you_are_not_notified_of_your_own_message(client, db_session):
                           headers={"Authorization": f"Bearer {owner}"})
     gid = g.json()["group_id"]
     for name in ("chatty_test", "quiet_test"):
-        await client.post(f"/v1/groups/{gid}/members/{name}", json={},
-                          headers={"Authorization": f"Bearer {owner}"})
+        await add_member(client, gid, name, {"Authorization": f"Bearer {owner}"})
 
     ids = {u.username: u.id for u in (await db_session.execute(
         select(User).where(User.username.in_(["operator", "chatty_test", "quiet_test"]))