Mark the place the map is pointed at, and make following work

Choosing a town moved the camera and then left the reader to work out which of
the settlements now on screen was the one they asked for. A town has no precise
position, so the map now marks its centre: a white disc under a coloured dot,
drawn as a style layer so the native renderer keeps it pinned through every pan
and zoom. The radar frames are inserted below it, because a band of rain must
not paint over the one thing that says which town this is.

A searched municipality becomes a PointTarget rather than being thrown away as
"the whole region". It is marked, the recentre button returns to it, and the
chip names it - but it is never persisted, so looking something up no longer
costs the user the place their app opens on. That was a real defect: searching
went through select(FreeTarget), which wrote null over the stored preference.

Following the device was broken outright. MapLibre reports a camera animation
the app started exactly as it reports the user grabbing the map, so engaging
follow and then animating to the position cancelled the follow it had just
started; the resulting FreeTarget then re-framed the whole region. Follow now
moves the camera first and switches tracking on second, and FreeTarget no longer
moves the camera as a reaction to the state changing - framing the region is an
action, so panning away while following keeps the view the user panned to.

Verified on the emulator with a fix in Turin: a searched town is marked and
saveable, the app reopens on it with the marker in place, following centres on
the blue dot, and panning stops the chase without yanking the map away.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Nuvolari/app/lib/features/map/map_overlay_controls.dart

@@ -44,6 +44,7 @@ class TargetSelector extends ConsumerWidget {
   const TargetSelector({
     required this.region,
     required this.onFollowRequested,
+    required this.onRegionRequested,
     required this.onSearch,
     required this.onManagePlaces,
     super.key,
@@ -56,6 +57,12 @@ class TargetSelector extends ConsumerWidget {
   /// owns the map handles it and only then changes the target.
   final VoidCallback onFollowRequested;
 
+  /// Framing the region is a camera move, and camera moves belong to the screen
+  /// that owns the map. Selecting the target alone cannot do it: the map lands
+  /// in the same state when the user simply drags away from what it was
+  /// following, and that must not throw their pan away.
+  final VoidCallback onRegionRequested;
+
   final VoidCallback onSearch;
   final VoidCallback onManagePlaces;
 
@@ -69,12 +76,16 @@ class TargetSelector extends ConsumerWidget {
     final label = switch (target) {
       FollowUser() => l10n.targetFollowMe,
       PlaceTarget(:final place) => place.name,
+      PointTarget(:final label) => label,
       FreeTarget() => l10n.targetWholeRegion(region.displayName),
     };
 
+    // A searched point gets the outlined pin: it is on the map like a saved
+    // place, but nothing has been kept, and the chip should not claim otherwise.
     final icon = switch (target) {
       FollowUser() => Icons.my_location,
       PlaceTarget() => Icons.place,
+      PointTarget() => Icons.place_outlined,
       FreeTarget() => Icons.map_outlined,
     };
 
@@ -90,9 +101,7 @@ class TargetSelector extends ConsumerWidget {
             case _ChooseFollow():
               onFollowRequested();
             case _ChooseRegion():
-              await ref
-                  .read(mapTargetProvider.notifier)
-                  .select(const FreeTarget());
+              onRegionRequested();
             case _ChoosePlace(:final place):
               await ref
                   .read(mapTargetProvider.notifier)
@@ -192,6 +201,7 @@ class MapActionButtons extends ConsumerWidget {
     final recentreIcon = switch (target) {
       FollowUser() => Icons.my_location,
       PlaceTarget() => Icons.place,
+      PointTarget() => Icons.place_outlined,
       FreeTarget() => Icons.zoom_out_map,
     };