feat: a group can be left out of Search, and Search tries every node

`search_listed` is a per-group setting on the node, changed by a signed
operator op and carried in the sealed handshake ack. Search reads it after
the handshake and stops there: no index is fetched, cached or merged, in any
of the four views, and the page says how many groups it left out. The switch
is a "Search" section in the group's settings, shown to the operator.

Absent means listed, at every layer: roster default, ack default, and the
client only drops a group on an explicit `false` — so an upgrade or an older
node removes nothing from anyone's Search.

It is a listing preference and protects nothing: the node serves the same
index to Search and to the group page and cannot tell them apart, every
member lists the group by opening it, and a client that ignores the flag
lists it in Search too. Design §9.11 says so, so it is never described as
private. The cost is one handshake per unlisted group, because only the node
knows the setting.

Search also took `nodes[0]` twice — for the index and for the pooled
connection — the defect 4cce50f fixed on the group page only. One
`connectToGroup` now walks the list the same way: a refusal about this
browser stops, `not_hosted` or a failed connection moves on.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XuNrwLf5EFWCMHzfoEvnpm

2 files changed, 8 insertions, 0 deletions

diff --git a/packages/meshbay-common/src/meshbay_common/adminop.py b/packages/meshbay-common/src/meshbay_common/adminop.py
index 8638e60..3e9fe11 100644
--- a/packages/meshbay-common/src/meshbay_common/adminop.py
+++ b/packages/meshbay-common/src/meshbay_common/adminop.py
@@ -99,6 +99,11 @@ OP_ROOT_REMOVE = "root_remove"
 OP_APP_DIRECTORIES = "app_directories"
 OP_CHAT_DIRECTORY = "chat_directory"
 OP_CHAT_LINK_PREVIEW = "chat_link_preview"
+# Whether this group's files appear in its members' cross-group Search. A
+# presentation choice and nothing more — every member still lists the group by
+# opening it — but it changes what every member's Search shows, so it is the
+# operator's, signed like the other per-group switches.
+OP_SEARCH_LISTED = "search_listed"
 # Open a new chat epoch for a group, by hand. The removals that matter open one
 # by themselves (member revoke/unpin, device revoke, gek_rotate); this is the
 # operator saying "do it anyway", which is the same shape as `gek_rotate` and
diff --git a/packages/meshbay-common/src/meshbay_common/protocol.py b/packages/meshbay-common/src/meshbay_common/protocol.py
index 1dfa519..f4cd497 100644
--- a/packages/meshbay-common/src/meshbay_common/protocol.py
+++ b/packages/meshbay-common/src/meshbay_common/protocol.py
@@ -223,6 +223,9 @@ class MNP:
     CHAT_DIRECTORY_ACK    = "chat_directory_ack"
     CHAT_LINK_PREVIEW     = "chat_link_preview"
     CHAT_LINK_PREVIEW_ACK = "chat_link_preview_ack"
+    # Whether the group's files are listed in members' cross-group Search.
+    SEARCH_LISTED         = "search_listed"
+    SEARCH_LISTED_ACK     = "search_listed_ack"
     # The keys a group's chat archive is encrypted under, on their way to a
     # member. Sealed under a group-derived subkey, so the payload carries an
     # authentication tag from a key the hub does not hold — and a member who has