Sessions Integration Feature

Nucleic-Session: FC94353F-9F0D-4BCC-AD7C-0FB14E38C2E5
Co-authored-by: Nucleic <[email protected]>

NucleicRemote/NucleicRemote/Models/RemoteStore.swift

@@ -461,13 +461,14 @@ final class RemoteStore: ObservableObject {
     }
 
     /// The callbacks one `HostConnection` uses to drive shared/aggregate state. `hostID` is captured
-    /// so a change updates the flat projection only for the active host, while badges, notifications,
-    /// and the single open transcript are handled globally across hosts.
+    /// so the open-transcript forwarding fires only for the Mac that owns the open session, while the
+    /// merged list/dashboard, badges, and notifications are rebuilt across every host on any change.
     private func callbacks(for hostID: String) -> HostConnection.Callbacks {
         var cb = HostConnection.Callbacks()
         cb.didUpdate = { [weak self] in
             guard let self else { return }
-            if hostID == self.activeHostID { self.mirrorActive() }
+            // Any host's change re-merges the aggregate the flat state binds to (mesh P3).
+            self.rebuildAggregate()
             self.refreshAggregate()
             self.flushPendingNotificationDecision()
             // A host that just connected (or reconnected) needs the current Live Activity token
@@ -475,22 +476,22 @@ final class RemoteStore: ObservableObject {
             self.syncLiveActivityRegistration()
         }
         cb.openSnapshot = { [weak self] snap in
-            guard let self, hostID == self.activeHostID, snap.summary.sessionID == self.openSessionID else { return }
+            guard let self, hostID == self.openSessionHostID, snap.summary.sessionID == self.openSessionID else { return }
             self.openEvents = snap.recentEvents
             self.openApprovals = snap.pendingApprovals
         }
         cb.openEvents = { [weak self] batch in
-            guard let self, hostID == self.activeHostID, batch.sessionID == self.openSessionID else { return }
+            guard let self, hostID == self.openSessionHostID, batch.sessionID == self.openSessionID else { return }
             self.openEvents.append(contentsOf: batch.events)
         }
         cb.openDiff = { [weak self] diff in
-            guard let self, hostID == self.activeHostID, diff.sessionID == self.openSessionID else { return }
+            guard let self, hostID == self.openSessionHostID, diff.sessionID == self.openSessionID else { return }
             self.openDiff = diff
             self.diffLoading = false
         }
         cb.approvalRequested = { [weak self] req, title in
             guard let self else { return }
-            if hostID == self.activeHostID, req.sessionID == self.openSessionID,
+            if hostID == self.openSessionHostID, req.sessionID == self.openSessionID,
                !self.openApprovals.contains(where: { $0.id == req.id }) {
                 self.openApprovals.append(req)
             }