Investigate Live Activity Session Load

Nucleic-Session: 044A9B93-AB31-4B6B-9A27-3631261269B1
Co-authored-by: Nucleic <[email protected]>

NucleicRemote/NucleicRemote/Models/RemoteStore.swift

@@ -929,6 +929,26 @@ final class RemoteStore: ObservableObject {
         connection(owningSession: sessionID)?.fetchFullTranscript(sessionID)
     }
 
+    /// Bind the open session to its owning Mac once that Mac is live — the deferred half of `open()`
+    /// for a session opened before any connection existed (a Live Activity / notification cold-launch
+    /// deep link). Because `open()` ran while the app was still dialing, `connection(owningSession:)`
+    /// found nothing: the host binding stayed nil, no `subscribe` went out, and the transcript
+    /// callbacks — all gated on `openSessionHostID` — dropped everything the host later sent, leaving
+    /// the detail stuck on "Disconnected" with an empty transcript and a dead composer. Once a host
+    /// connects and lists its sessions, `didUpdate` calls this: it finds the owner and finishes the
+    /// subscription so the transcript loads and connectivity/scope follow the bound host. Idempotent
+    /// and cheap — a no-op on the common path where `open()` already bound a live connection.
+    private func bindOpenSessionIfNeeded() {
+        guard !demoMode, let sessionID = openSessionID,
+              let conn = connection(owningSession: sessionID), conn.connectivity.isLive else { return }
+        // Already bound to this live host with its subscription in place — nothing to redo.
+        guard openSessionHostID != conn.hostID || conn.openSessionID != sessionID else { return }
+        openSessionHostID = conn.hostID
+        conn.openSessionID = sessionID
+        conn.send(.subscribe(Subscribe(sessionID: sessionID, sinceSeq: nil, verbosity: .full)))
+        conn.fetchFullTranscript(sessionID)
+    }
+
     /// Ask the host for the open session's full patch (Diff tab). No-op when the host
     /// doesn't advertise the capability — the view falls back to the diffstat summary.
     func fetchDiff(_ sessionID: SessionID) {