closeTab method
Tab close karo. Agar active tab close ho raha hai → previous tab activate (ya null)
Implementation
void closeTab(String route) {
final idx = _tabs.indexWhere((t) => t.route == route);
if (idx == -1) return;
_tabs.removeAt(idx);
if (_activeRoute == route) {
if (_tabs.isEmpty) {
_activeRoute = null;
} else {
// Previous tab ko activate karo
final newIdx = (idx - 1).clamp(0, _tabs.length - 1);
_activeRoute = _tabs[newIdx].route;
}
}
notifyListeners();
}