fix(node): how a hosted group admits people is the operator's, not the hub's

attach_group no longer copies join_policy and visibility from the hub's
answer: they come with the operator's request (the desktop creation form,
`group add --open`) and default to invite/private; the CLI says when the hub
lists the group otherwise. Every string written into node.toml is escaped
(toml_string) and read back through tomllib, so a group or folder name cannot
write lines of its own (F-17).

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

1 files changed, 4 insertions, 1 deletions

diff --git a/packages/meshbay-client/src/main.js b/packages/meshbay-client/src/main.js
index 309d5f6..236a285 100644
--- a/packages/meshbay-client/src/main.js
+++ b/packages/meshbay-client/src/main.js
@@ -2184,7 +2184,10 @@ function registerBridge() {
     attachGroup: async (a) => {
       const body = { name: aText(a.name, 'the group name'),
                      shared_dir: aText(a.path, 'the folder', 4096),
-                     writable: a.writable !== false };
+                     writable: a.writable !== false,
+                     // The person's choice on the creation form; the node never
+                     // takes it from the hub.
+                     join_policy: a.joinPolicy === 'open' ? 'open' : 'invite' };
       await confirmOrRefuse('native.attach_confirm',
                             { name: body.name, path: body.shared_dir });
       return ['POST', '/api/groups/attach', body];