port(smarm): track HEAD efbc254 — RFC 014/015 API sync

- gen_server rename (RFC 015, 3e31606): ServerRef/ServerCtx/ServerBuilder
  -> GenServerRef/GenServerCtx/GenServerBuilder across conn_actor,
  conn_registry, serve, pubsub, channels::session.
- type Timer = () on the three GenServer impls (RFC 015, 57eadb5);
  handle_timer/handle_idle/tick_every stay defaulted — opt-in later.
- Watcher and GenServerCtx are now generic over the server type: watcher
  fields typed Watcher<Table<M>> / Watcher<Registry<P, K>>; Registry's
  struct bounds strengthened to its GenServer impl bounds
  (P: Encode + Decode + Send + Sync + 'static, K: SessionKey) so the
  Watcher field's G: GenServer bound is satisfiable at the declaration.
- RFC 014 (a866e34) registry: register is (Name<M>, Sender<M>), self-only
  — a name is a typed messaging endpoint, not a pid tag. The
  introspection-only urus.server / urus.listener.{i} bindings are dropped
  rather than faked with unit channels; the whereis integration test is
  deleted; a proper messageable-name design is icebox'd in ROADMAP.md.
- Audit vs smarm 6c2b7e9 (queued messages dropped when Receiver drops):
  pubsub's prune-on-send-failure retain still holds — send Errs once
  receiver_alive is false, so a dropped rx prunes on next broadcast,
  exactly what subscriber_count's doc already promised. Freeing stranded
  Arc<M> broadcasts is strictly good. No change needed.
- The 7x E0283 in channels/mod.rs were cascade fallout of the generics
  changes; dissolved with the port, as discovery predicted.

Suite: 90 lib + 45 integration + 2 doc, green under default, smarm-trace,
phoenix, and all-features. 3 pre-existing clippy lints (conn.rs,
parser.rs, conn_actor.rs; clippy 1.97 strictness) deferred to a follow-up
chore commit to keep this diff pure.

src/serve.rs

@@ -17,7 +17,7 @@ use crate::conn_registry::{self, Call, Cast, ConnRegistry, Reply};
 use crate::net::{accept_nonblocking, bind_and_listen, OwnedFd};
 use crate::plug::Pipeline;
 
-use smarm::{ChildSpec, OneForOne, Restart, ServerRef, Strategy};
+use smarm::{ChildSpec, OneForOne, Restart, GenServerRef, Strategy};
 
 use std::io::{self, ErrorKind};
 use std::net::{SocketAddr, ToSocketAddrs};
@@ -125,7 +125,7 @@ fn listener_loop(
     listener: Arc<OwnedFd>,
     pipeline: Pipeline,
     limits: ConnLimits,
-    registry: ServerRef<ConnRegistry>,
+    registry: GenServerRef<ConnRegistry>,
     shutdown: Arc<AtomicBool>,
 ) {
     let fd = listener.as_raw();
@@ -327,15 +327,6 @@ pub fn serve_with_shutdown(
             let sf = shutdown_flag.clone();
             sup = sup.child(ChildSpec::new(Restart::Transient, move || {
                 println!("urus: listener {} starting", i);
-                // Named for whereis-style introspection. On a restart the
-                // old binding points at a dead pid; smarm's registry
-                // evicts stale bindings lazily, so re-registering the
-                // same name is fine. Ignore the result — a registry
-                // hiccup must not take the listener down.
-                let _ = smarm::register(
-                    format!("urus.listener.{i}"),
-                    smarm::self_pid(),
-                );
                 listener_loop(lfd.clone(), p.clone(), limits, r.clone(), sf.clone());
             }));
         }
@@ -343,11 +334,13 @@ pub fn serve_with_shutdown(
         // faster than that trips the cap and tears the pool down — loud
         // failure over a zombie server.
         let sup_h = smarm::spawn(move || sup.run());
-        // Register via the JoinHandle's pid rather than inside the
-        // closure: the binding exists before the supervisor body runs a
-        // single instruction, so an early `whereis("urus.server")` can't
-        // race a None. Result ignored for the same reason as listeners.
-        let _ = smarm::register("urus.server", sup_h.pid());
+        // The old `urus.server` / `urus.listener.{i}` name registrations
+        // are gone with smarm's RFC 014 registry rework: `register` is now
+        // `(Name<M>, Sender<M>)`, self-only — a name is a typed messaging
+        // endpoint, not a pid tag. urus's bindings were introspection-only
+        // with no channel behind them, so they were dropped rather than
+        // faked with a unit channel. A real messageable `urus.server`
+        // name is in the icebox (ROADMAP.md).
 
         // Block until told to shut down. We poll `try_recv` + `sleep`
         // rather than parking in `recv`: a smarm `Sender::send` from a
@@ -399,7 +392,7 @@ pub fn serve_with_shutdown(
             }
         }
 
-        // 5. Our ServerRef drops here. The registry's inbox closes once
+        // 5. Our GenServerRef drops here. The registry's inbox closes once
         //    the last conn's clone drops with it, and the runtime winds
         //    down when the last actor exits.
     });