fix: use synchronous notification delivery and add NSLog diagnostics for editor teardown

Author: datlechin

TablePro/Views/Editor/SQLEditorCoordinator.swift

@@ -72,11 +72,14 @@ final class SQLEditorCoordinator: TextViewCoordinator {
     /// Subscribe to coordinator teardown notifications for this connection.
     func observeTeardown(connectionId: UUID) {
         self.connectionId = connectionId
+        NSLog("[SQLEditorCoordinator] observeTeardown registered for %@", connectionId.uuidString)
         teardownObserver = NotificationCenter.default.addObserver(
             forName: MainContentCoordinator.editorTeardownNotification,
             object: nil,
-            queue: .main
+            queue: nil  // Synchronous delivery on posting thread (main)
         ) { [weak self] notification in
+            NSLog("[SQLEditorCoordinator] teardown notification received, self=%@",
+                  self == nil ? "nil" : "alive")
             guard let self,
                   let notifConnectionId = notification.object as? UUID,
                   notifConnectionId == connectionId else { return }