Route distance timeout warning

lib/app_state.dart

@@ -114,6 +114,8 @@ class AppState extends ChangeNotifier {
   bool get settingRouteStart => _navigationState.settingRouteStart;
   bool get isSettingSecondPoint => _navigationState.isSettingSecondPoint;
   bool get areRoutePointsTooClose => _navigationState.areRoutePointsTooClose;
+  double? get distanceFromFirstPoint => _navigationState.distanceFromFirstPoint;
+  bool get distanceExceedsWarningThreshold => _navigationState.distanceExceedsWarningThreshold;
   bool get isCalculating => _navigationState.isCalculating;
   bool get showingOverview => _navigationState.showingOverview;
   String? get routingError => _navigationState.routingError;

lib/dev_config.dart

@@ -128,6 +128,7 @@ const double kNodeProximityWarningDistance = 15.0; // meters - distance threshol
 
 // Navigation route planning configuration
 const double kNavigationMinRouteDistance = 100.0; // meters - minimum distance between start and end points
+const double kNavigationDistanceWarningThreshold = 20000.0; // meters - distance threshold for timeout warning (30km)
 
 // Node display configuration
 const int kDefaultMaxNodes = 500; // Default maximum number of nodes to render on the map at once

lib/state/navigation_state.dart

@@ -87,6 +87,24 @@ class NavigationState extends ChangeNotifier {
     return distance < kNavigationMinRouteDistance;
   }
   
+  /// Get distance from first navigation point to provisional location during second point selection
+  double? get distanceFromFirstPoint {
+    if (!_isSettingSecondPoint || _provisionalPinLocation == null) return null;
+    
+    final firstPoint = _nextPointIsStart ? _routeEnd : _routeStart;
+    if (firstPoint == null) return null;
+    
+    return const Distance().as(LengthUnit.Meter, firstPoint, _provisionalPinLocation!);
+  }
+  
+  /// Check if distance between points would likely cause timeout issues
+  bool get distanceExceedsWarningThreshold {
+    final distance = distanceFromFirstPoint;
+    if (distance == null) return false;
+    
+    return distance > kNavigationDistanceWarningThreshold;
+  }
+  
   /// BRUTALIST: Single entry point to search mode
   void enterSearchMode(LatLng mapCenter) {
     debugPrint('[NavigationState] enterSearchMode - current mode: $_mode');

lib/widgets/navigation_sheet.dart

@@ -161,7 +161,50 @@ class NavigationSheet extends StatelessWidget {
                   coordinates: provisionalLocation,
                   address: provisionalAddress,
                 ),
-                const SizedBox(height: 16),
+                const SizedBox(height: 8),
+                
+                // Show distance from first point
+                if (appState.distanceFromFirstPoint != null) ...[
+                  Text(
+                    'Distance: ${(appState.distanceFromFirstPoint! / 1000).toStringAsFixed(1)} km',
+                    style: TextStyle(
+                      fontSize: 14,
+                      fontWeight: FontWeight.w500,
+                      color: Colors.grey[600],
+                    ),
+                  ),
+                  const SizedBox(height: 8),
+                ],
+                
+                // Show distance warning if threshold exceeded
+                if (appState.distanceExceedsWarningThreshold) ...[
+                  Container(
+                    padding: const EdgeInsets.all(12),
+                    decoration: BoxDecoration(
+                      color: Colors.amber.withOpacity(0.1),
+                      borderRadius: BorderRadius.circular(8),
+                      border: Border.all(color: Colors.amber.withOpacity(0.3)),
+                    ),
+                    child: Row(
+                      crossAxisAlignment: CrossAxisAlignment.start,
+                      children: [
+                        Icon(Icons.warning_amber, color: Colors.amber[700], size: 20),
+                        const SizedBox(width: 8),
+                        Expanded(
+                          child: Text(
+                            'Trips longer than ${(kNavigationDistanceWarningThreshold / 1000).toStringAsFixed(0)} km are likely to time out. We are working to improve this; stay tuned.',
+                            style: TextStyle(
+                              fontSize: 14,
+                              color: Colors.amber[700],
+                            ),
+                          ),
+                        ),
+                      ],
+                    ),
+                  ),
+                  const SizedBox(height: 8),
+                ],
+                
                 
                 // Show warning message if locations are too close
                 if (appState.areRoutePointsTooClose) ...[