feat(maestro): daemon broker T2 + pair-JWT verifier + allow_inbound (NAP-247)

* New PairAttachVerifier (crates/maestro-daemon/src/jwt.rs): checks
  signature, aud == self, exp > now, and sub ∈ allow_inbound. Default
  deny — empty allow_inbound rejects every cross-daemon attach.
* /sessions/:id/stream tries the legacy verifier first, falls back to
  the pair verifier on mismatch. Compat with existing direct-attach.
* New BrokerHandle (crates/maestro-daemon/src/broker.rs): shared between
  the registry-client task and HTTP handlers; calls ResolveAttach over
  the control link and correlates the reply via a pending map.
* RegistryClient now owns a BrokerHandle, drains its outbound mpsc
  alongside session events / heartbeats, and routes
  ResolveAttachResult back into the pending map. First heartbeat fires
  immediately so the registry has the daemon's perimeter info before
  the first ResolveAttach.
* /api/attach/🆔 self-owned → local PTY; peer-owned (per catalog
  mirror) → ResolveAttach + T2 dial + bidirectional frame proxy.
  Returns structured errors for missing local perimeter, peer on a
  different perimeter, etc. T1/T3 stay stubbed.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/maestro-daemon/tests/local_api.rs

@@ -11,7 +11,7 @@ use std::time::Duration;
 
 use common::DaemonFixture;
 use futures_util::{SinkExt, StreamExt};
-use maestro_daemon::{local_api, CatalogMirror};
+use maestro_daemon::{local_api, BrokerHandle, CatalogMirror};
 use maestro_protocol::{CreateSessionRequest, DaemonInfo, RegistryEvent, Session};
 use tokio::net::TcpListener;
 use tokio::sync::oneshot;
@@ -34,7 +34,18 @@ async fn spawn(daemon_id: &str, hostname: &str, daemon_url: &str) -> Harness {
     let manager = fx.manager.clone();
     let catalog = CatalogMirror::new();
     let state = local_api::state_for(manager.clone(), hostname, daemon_url, catalog.clone());
-    let router = local_api::router(state).merge(local_api::broker_router(manager.clone()));
+    // NAP-247: tests don't exercise the cross-host broker path; hand the
+    // router an isolated BrokerHandle whose receiver is dropped, so any
+    // resolve_attach attempt fails fast with NoControlLink.
+    let (broker, _broker_rx) = BrokerHandle::new();
+    let broker_state = local_api::BrokerState {
+        manager: manager.clone(),
+        catalog: catalog.clone(),
+        broker,
+        self_daemon_id: std::sync::Arc::new(daemon_id.into()),
+        self_perimeter_id: None,
+    };
+    let router = local_api::router(state).merge(local_api::broker_router(broker_state));
     let listener = TcpListener::bind(SocketAddr::from((Ipv4Addr::LOCALHOST, 0)))
         .await
         .unwrap();