♻️ refactor: enhance discount handling and transport mode UX persistence

- Add passenger state management when setting discount type
- Fix location search loading indicator timing with post-frame callback
- Load saved transport mode preferences on modal initialization
- Clean up injection.config.dart formatting

Author: MasuRii

lib/src/core/di/injection.config.dart

@@ -6,6 +6,7 @@ import 'package:latlong2/latlong.dart';
 import '../../core/di/injection.dart';
 import '../../core/errors/failures.dart';
 import '../../core/hybrid_engine.dart';
+import '../../models/discount_type.dart';
 import '../../models/fare_formula.dart';
 import '../../models/fare_result.dart';
 import '../../models/location.dart';
@@ -140,9 +141,22 @@ class MainScreenController extends ChangeNotifier {
     return _settingsService.hasSetDiscountType();
   }
 
-  /// Set user discount type preference
-  Future<void> setUserDiscountType(dynamic discountType) async {
+  /// Set user discount type preference and update local passenger state.
+  Future<void> setUserDiscountType(DiscountType discountType) async {
     await _settingsService.setUserDiscountType(discountType);
+
+    // Update local passenger counts based on the selected discount type
+    // Assuming a total of 1 passenger when first setting the preference
+    if (discountType == DiscountType.discounted) {
+      _regularPassengers = 0;
+      _discountedPassengers = 1;
+    } else {
+      _regularPassengers = 1;
+      _discountedPassengers = 0;
+    }
+    _passengerCount = _regularPassengers + _discountedPassengers;
+
+    notifyListeners();
   }
 
   /// Search locations with debounce for autocomplete

lib/src/presentation/controllers/main_screen_controller.dart

@@ -222,8 +222,11 @@ class _LocationFieldState extends State<_LocationField> {
       final results = await widget.onSearchLocations(query);
       return results;
     } finally {
-      // Clear loading state after fetching (success or error)
-      _isSearching.value = false;
+      // Delay clearing the loading state until after the current frame completes
+      // so the autocomplete options have time to render before the spinner disappears.
+      WidgetsBinding.instance.addPostFrameCallback((_) {
+        _isSearching.value = false;
+      });
     }
   }
 

lib/src/presentation/widgets/main_screen/location_input_section.dart

@@ -68,6 +68,23 @@ class _TransportModeSelectionModalState
   void initState() {
     super.initState();
     _groupedFormulas = _groupFormulas();
+    _loadSavedPreferences();
+  }
+
+  /// Loads saved transport mode preferences and initializes selected modes.
+  /// Modes that are NOT in the hidden set should be marked as selected.
+  Future<void> _loadSavedPreferences() async {
+    final hiddenModes = await widget.settingsService.getHiddenTransportModes();
+
+    setState(() {
+      for (final formula in widget.availableFormulas) {
+        final modeSubTypeKey = '${formula.mode}::${formula.subType}';
+        // Mode is selected if it's NOT hidden
+        if (!hiddenModes.contains(modeSubTypeKey)) {
+          _selectedModes.add(modeSubTypeKey);
+        }
+      }
+    });
   }
 
   Map<String, List<FareFormula>> _groupFormulas() {