Smooth boosted fleet travel

controllers/GameController.gd

@@ -103,6 +103,13 @@ var keyboard_steering: bool = false
 
 
 func _ready() -> void:
+	# Most visuals still animate per rendered frame. The main/surface scenes opt
+	# their roots out of global interpolation, then opt their physics-follow
+	# camera and Ship.tscn hulls back in.
+	# Running the camera after ordinary physics nodes lets it follow the ships'
+	# newest centroid, and interpolation fills the display frames in between.
+	process_physics_priority = 1
+	camera.reset_physics_interpolation()
 	# #148: the main theme, which outlives this scene - see Music.ensure().
 	# This script is the root of BOTH the space scene and the planet
 	# surface, so one call here covers the whole game.
@@ -292,7 +299,7 @@ func _process(delta: float) -> void:
 	_update_pivot(delta)
 
 	# Keep the heading fresh while a control is held. Fleet advances its own
-	# anchor in _process, so this only needs to report the direction. The
+	# anchor in _physics_process, so this only needs to report the direction. The
 	# keyboard takes precedence, and releasing the keys has to stop the fleet
 	# itself - unlike the stick, there is no centred-again signal to hook.
 	# #124: the breach drives. One check here covers the stick, the keyboard
@@ -303,6 +310,12 @@ func _process(delta: float) -> void:
 	else:
 		_apply_steering()
 
+
+func _physics_process(delta: float) -> void:
+	_update_camera(delta)
+
+
+func _update_camera(delta: float) -> void:
 	var target: Vector2 = fleet.get_centroid()
 	if camera.global_position.distance_to(target) <= camera_snap_distance:
 		# Snap and stop dead - see camera_snap_distance. Assigning the exact