Fix map jitter when touching map during follow-me animations

Cancel in-progress follow-me animations on pointer-down and suppress
new ones while any pointer is on the map. Without this, GPS position
updates trigger 600ms animateTo() calls that fight with the user's
stationary finger, causing visible wiggle — especially at low zoom
where small geographic shifts cover more pixels.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

lib/widgets/map/gps_controller.dart

@@ -32,6 +32,7 @@ class GpsController {
   List<OsmNode> Function()? _getNearbyNodes;
   List<NodeProfile> Function()? _getEnabledProfiles;
   VoidCallback? _onMapMovedProgrammatically;
+  bool Function()? _isUserInteracting;
 
   /// Get the current GPS location (if available)
   LatLng? get currentLocation => _currentLocation;
@@ -49,6 +50,7 @@ class GpsController {
     required List<OsmNode> Function() getNearbyNodes,
     required List<NodeProfile> Function() getEnabledProfiles,
     VoidCallback? onMapMovedProgrammatically,
+    bool Function()? isUserInteracting,
   }) async {
     debugPrint('[GpsController] Initializing GPS controller');
     
@@ -61,7 +63,8 @@ class GpsController {
     _getNearbyNodes = getNearbyNodes;
     _getEnabledProfiles = getEnabledProfiles;
     _onMapMovedProgrammatically = onMapMovedProgrammatically;
-    
+    _isUserInteracting = isUserInteracting;
+
     // Start location tracking
     await _startLocationTracking();
   }
@@ -235,9 +238,10 @@ class GpsController {
     if (followMeMode == FollowMeMode.off || _mapController == null) {
       return;
     }
-    
     WidgetsBinding.instance.addPostFrameCallback((_) {
       try {
+        if (_isUserInteracting?.call() == true) return;
+
         if (followMeMode == FollowMeMode.follow) {
           // Follow position, preserve rotation
           _mapController!.animateTo(
@@ -352,5 +356,6 @@ class GpsController {
     _getNearbyNodes = null;
     _getEnabledProfiles = null;
     _onMapMovedProgrammatically = null;
+    _isUserInteracting = null;
   }
 }