feat(cluster): RFC 010 c10–c16, follow-ups and Phase 6 (squash of 16ef583..d9c62a8)

Tree snapshot of d9c62a8 (2026-08-18). The 20 source commits between
16ef583 (c9) and d9c62a8 were never pushed and the clone that held them
was lost; this commit carries their combined tree verbatim so the build
history stays auditable from the c1–c9 commits below it. Original
hashes as recorded in the session handoff:

  c10  f03e94d  pid targeting + auto-serialization (RemotePid, D14 name
                on the wire); Phase 3 gate
  c11  7ef4bad  DownReason::Disconnected, wire tag 5
  c12  d124162  remote monitors (Monitor/Demonitor/Down frames)
  c13  9de967b  connection-loss synthesis (A+B: Monitors::teardown +
                unread-command Disconnected); Phase 4 gate
  c14  7e822b7  eager pg eviction (reaper actor, ReaperInboxes)
       dbe1a22  InboundVerdict::label(), trace::Event::ClusterInbound
       31a9877  tests/channel.rs monitor-churn target gated on `go`
       653559e  Discovery::Withdrawn{name, addr}
  c15  b41d76e  distributed pg: Sync on NodeUp, Join/Leave broadcast,
                NodeDown sweep, members_all; PgMsg wire type
  c16  fafa881  pick_any / dispatch_any; Phase 5 complete
  Phase 6 Tier A:
       195c73e  p4  NodeEvent::NodeDown(NodeInfo)
       48fd766  p1  connector Candidate{name, addr, state}
       ce8cf99  p2+p7 conn.rs select arms as Vec<Arm>; Outbound::Drained
       bf24988  p6  RemotePid::from_local -> Option
       9ae0380  p3  PeerStanding{Free, Claimed, Dialing}
       c7d62a1  p11 cluster::Timing knobs, threaded by value
       46f171d  p11 cluster_disconnect un-ignored on SMARM_FAST_TIMING
  Phase 6 Tier B:
       391a9ae  p5  cluster::RemoteDownReason{Local, Disconnected};
                    DownReason::Disconnected removed from core
       7ddd908  p9  pg ctl channel unconditional, one cfg seam at spawn
       d9c62a8      PeerNameMismatch parks the candidate; ClusterDial trace

Verified at d9c62a8: default 361/0, cluster 448/0, clippy --lib on
default / cluster / cluster+smarm-trace, fmt, 10x flake on
cluster_dial_mismatch, 5x on cluster_pg.

tests/cluster_mesh.rs

@@ -24,9 +24,7 @@ mod common;
 use common::{maybe_child, spawn_node, Node};
 use smarm::cluster::envelope::NodeMeta;
 use smarm::cluster::membership::{subscribe, NodeEvent};
-use smarm::cluster::{start, Config, StaticSeeds};
-use smarm::pg::NodeId;
-use std::collections::HashMap;
+use smarm::cluster::{start, Config, StaticSeeds, Timing};
 use std::time::Duration;
 
 const ROLES: &[(&str, fn())] = &[("node", role_node)];
@@ -56,21 +54,19 @@ fn role_node() {
             },
             listen_addr: listen,
             strategy: Box::new(StaticSeeds::new(seeds)),
+            timing: Timing::default(),
         })
         .expect("listener binds");
         println!("LISTENING {}", cluster.local_addr());
 
         let events = subscribe().expect("manager is up");
-        let mut names: HashMap<NodeId, String> = HashMap::new();
         loop {
             match events.rx.recv() {
                 Ok(NodeEvent::NodeUp(info)) => {
-                    names.insert(info.node, info.name.clone());
                     println!("MEMBER-UP {} inc={}", info.name, info.incarnation.get());
                 }
-                Ok(NodeEvent::NodeDown { node }) => {
-                    let name = names.remove(&node).unwrap_or_else(|| "?".to_string());
-                    println!("MEMBER-DOWN {name}");
+                Ok(NodeEvent::NodeDown(info)) => {
+                    println!("MEMBER-DOWN {}", info.name);
                 }
                 Err(_) => break, // manager gone; park below regardless
             }