add build step for flutter web, add persistent pagination in the traction list

lib/components/pages/new_entry/new_entry_page.dart

@@ -128,10 +128,6 @@ class _NewEntryPageState extends State<NewEntryPage> {
     }
   }
 
-  double _manualMilesFromInput(DistanceUnitService units) {
-    return units.milesFromInput(_mileageController.text) ?? 0;
-  }
-
   double _milesFromInputWithUnit(DistanceUnit unit) {
     return DistanceFormatter(unit)
             .parseInputMiles(_mileageController.text.trim()) ??
@@ -276,6 +272,7 @@ class _NewEntryPageState extends State<NewEntryPage> {
         ),
       ),
     );
+    if (!mounted) return;
     if (result != null) {
       final units = _distanceUnits(context);
       setState(() {
@@ -1536,43 +1533,6 @@ class _NewEntryPageState extends State<NewEntryPage> {
     );
   }
 
-  Widget _timeToggleBlock({
-    required String label,
-    required bool value,
-    required ValueChanged<bool?>? onChanged,
-    required String matchLabel,
-    required bool matchValue,
-    required ValueChanged<bool?>? onMatchChanged,
-    required bool showMatch,
-    Widget? picker,
-  }) {
-    return Column(
-      crossAxisAlignment: CrossAxisAlignment.start,
-      children: [
-        CheckboxListTile(
-          value: value,
-          onChanged: onChanged,
-          dense: true,
-          contentPadding: EdgeInsets.zero,
-          controlAffinity: ListTileControlAffinity.leading,
-          title: Text(label),
-        ),
-        if (showMatch)
-          CheckboxListTile(
-            value: matchValue,
-            onChanged: onMatchChanged,
-            dense: true,
-            contentPadding: const EdgeInsets.only(left: 12),
-            controlAffinity: ListTileControlAffinity.leading,
-            title: Text(matchLabel),
-          ),
-        if (picker != null) ...[
-          const SizedBox(height: 6),
-          picker,
-        ],
-      ],
-    );
-  }
 }
 
 class _UpperCaseTextFormatter extends TextInputFormatter {

lib/components/pages/new_entry/new_entry_submit_logic.dart

@@ -52,6 +52,7 @@ extension _NewEntrySubmitLogic on _NewEntryPageState {
     if (form == null) return;
     if (!form.validate()) return;
     if (!await _validateRequiredFields()) return;
+    if (!mounted) return;
     final routeStations = _routeResult?.calculatedRoute ?? [];
     final startVal = _useManualMileage
         ? _startController.text.trim()