Add error logging to SessionRow terminate function

Previously, when session termination failed from the X button in the list view,
the error was silently swallowed. This made it difficult to diagnose why
termination might fail compared to the menu action which has proper logging.

Now both termination paths log errors consistently, making debugging easier.

mac/VibeTunnel/Presentation/Components/Menu/SessionRow.swift

@@ -360,6 +360,7 @@ struct SessionRow: View {
                 // The session monitor will automatically update
             } catch {
                 // Handle error
+                Self.logger.error("Failed to terminate session \(session.key): \(error)")
                 await MainActor.run {
                     isTerminating = false
                 }