fix(broker): don't broadcast peer_joined/peer_left/peer_returned to same-pubkey sessions

When a user opens multiple Claude Code instances on one laptop they
all share the same memberPubkey (one identity, one config.json). The
broker was broadcasting each Claude Code start/stop to every OTHER
session of the same user — showing as 'peer agutierrez left / joined'
spam in every active claude terminal.

Now: skip broadcast to presences whose memberPubkey equals the joining
or leaving presence's memberPubkey. Other actual peers on the mesh
still see the event.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/broker/src/index.ts

@@ -2001,6 +2001,10 @@ function handleConnection(ws: WebSocket): void {
           for (const [pid, peer] of connections) {
             if (pid === presenceId) continue;
             if (peer.meshId !== joinedConn.meshId) continue;
+            // Don't spam the user's own other sessions about themselves —
+            // multiple Claude Code instances from one laptop all share the
+            // same memberPubkey, so they're the same human identity.
+            if (peer.memberPubkey === joinedConn.memberPubkey) continue;
             sendToPeer(pid, joinMsg);
           }
           // Restore persistent MCP servers owned by this member
@@ -4162,6 +4166,9 @@ function handleConnection(ws: WebSocket): void {
         };
         for (const [pid, peer] of connections) {
           if (peer.meshId !== conn.meshId) continue;
+          // Don't tell the user's own other sessions they "left" when one
+          // of their Claude Code instances closes. Same pubkey = same user.
+          if (peer.memberPubkey === conn.memberPubkey) continue;
           sendToPeer(pid, leaveMsg);
         }
       }