Fix SelectTool: preserve movement validation after direct selection

Ensure non-movable objects remain non-movable when selected through
direct selection. Continue through __move_or_resize_object validation
flow instead of early return to maintain proper permission checks.

Fixes #29

Author: PierreRaybaut

plotpy/events.py

@@ -1506,11 +1506,11 @@ def start_tracking(self, filter: StatefulEventFilter, event: QC.QEvent) -> None:
                         self.active = nearest
                         self.handle = nearest_handle
                         self.inside = nearest_inside
+                        # Update distance for the new object
+                        dist = nearest_dist
                         # Clear unselection pending since we've switched to a new object
                         self.unselection_pending = False
-                        # No need to process further - we've completed the selection
-                        plot.replot()
-                        return
+                        # Continue to move_or_resize_object for proper validation
                     else:
                         # Clicked on empty space - unselect everything
                         self.__unselect_objects(filter)