Merge the nostr rendezvous reorg into the next line

Forward-merge the src/nostr / src/mdns rendezvous reorganization
(relocation out of src/discovery/, the Discovery->Rendezvous rename, the
RendezvousDriver consolidation, and the trace-target reference updates)
onto the next branch. The sole conflict was in the LAN poll method's
doc-comment and signature: kept next's XX-handshake wording and applied
the lan_rendezvous rename. Merged tree builds clean; next lib suite 1583
passing, fmt/clippy clean.

src/control/queries.rs

@@ -236,7 +236,7 @@ pub fn show_peers(node: &Node) -> Value {
     // Per-npub Nostr-traversal failure-state snapshot, indexed by npub
     // for O(1) per-peer lookup. Empty if Nostr discovery is disabled.
     let nostr_state: std::collections::HashMap<String, _> = node
-        .nostr_discovery_handle()
+        .nostr_rendezvous_handle()
         .map(|d| {
             d.failure_state_snapshot()
                 .into_iter()