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

1 files changed, 20 insertions, 0 deletions

diff --git a/packages/meshbay-node/src/meshbay_node/ops.py b/packages/meshbay-node/src/meshbay_node/ops.py
index 91a922a..8cd893c 100644
--- a/packages/meshbay-node/src/meshbay_node/ops.py
+++ b/packages/meshbay-node/src/meshbay_node/ops.py
@@ -1733,6 +1733,26 @@ async def set_chat_link_preview(state: dict, group_id: str,
     return {"enabled": enabled, "group_id": group_id}
 
 
+async def set_search_listed(state: dict, group_id: str, listed: bool) -> dict:
+    """
+    Whether this group's files appear in members' cross-group Search.
+
+    A presentation choice, and it must never be described as more: a member
+    still lists the whole group by opening it, the node serves the index
+    exactly as before, and a client that ignores the flag lists the group in
+    Search too. What it buys is a family album not turning up in the middle of
+    a film library. Absent means listed.
+    """
+    roster = _roster(state)
+    ctx = _group_ctx(state, group_id)
+    await roster.set_search_listed(group_id, listed,
+                                   set_by=state.get("node_user_id", ""))
+    ctx["search_listed"] = listed
+    log.info("Search listing for group %s: %s", group_id[:8],
+             "on" if listed else "off")
+    return {"listed": listed, "group_id": group_id}
+
+
 # ── Scan settings ────────────────────────────────────────────────────────────
 
 async def set_scan_settings(state: dict, group_id: str, reconcile_interval_secs: float,