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, 3 deletions

diff --git a/packages/meshbay-hub/tests/test_group_hosting.py b/packages/meshbay-hub/tests/test_group_hosting.py
index c6111f2..7aa6bd1 100644
--- a/packages/meshbay-hub/tests/test_group_hosting.py
+++ b/packages/meshbay-hub/tests/test_group_hosting.py
@@ -17,6 +17,7 @@ import hashlib
 from datetime import UTC, datetime, timedelta
 
 import pytest
+from membership import add_member
 from meshbay_hub.db.models import Group, GroupMember
 from meshbay_hub.tasks.cleanup import find_unhosted_groups, prune_unhosted_groups
 from sqlalchemy import select
@@ -72,7 +73,7 @@ async def test_a_member_does_not_see_an_unhosted_group(client):
     owner = await _user(client, "setup2_test")
     member = await _user(client, "early_bird")
     gid = (await _group(client, owner, "premature")).json()["group_id"]
-    await client.post(f"/v1/groups/{gid}/members/early_bird", json={}, headers=owner)
+    await add_member(client, gid, 'early_bird', owner)
 
     mine = await client.get("/v1/groups/mine", headers=member)
     assert [g["name"] for g in mine.json()["groups"]] == []
@@ -83,7 +84,7 @@ async def test_a_member_sees_it_once_a_node_has_announced_it(client, db_session)
     owner = await _user(client, "setup3_test")
     member = await _user(client, "patient_test")
     gid = (await _group(client, owner, "ready")).json()["group_id"]
-    await client.post(f"/v1/groups/{gid}/members/patient_test", json={}, headers=owner)
+    await add_member(client, gid, 'patient_test', owner)
 
     await _mark_hosted(db_session, gid)
 
@@ -174,7 +175,7 @@ async def test_collecting_a_group_takes_its_memberships_with_it(client, db_sessi
     owner = await _user(client, "reaper5_test")
     await _user(client, "tagalong")
     gid = (await _group(client, owner, "doomed")).json()["group_id"]
-    await client.post(f"/v1/groups/{gid}/members/tagalong", json={}, headers=owner)
+    await add_member(client, gid, 'tagalong', owner)
 
     g = await db_session.get(Group, gid)
     g.created_at = datetime.now(UTC) - timedelta(days=9)