fix(hud): have game mode hand HUD its target ship instead of group lookup

HUDController found its ship via get_first_node_in_group("ship"), a group
that has 2+ members once a match has an AI opponent — it only worked
because the player ship happened to spawn first. spawn_camera_rig now
wires the HUD's ship the same way it already wires the camera rig's
target.

Game/scripts/game_mode.gd

@@ -13,6 +13,7 @@ extends Node3D
 const CAMERA_RIG_SCENE = preload("res://scenes/ship_camera_rig.tscn")
 
 var arena: Arena
+var hud: HUDController
 var ball: RigidBody3D
 var ships: Array[Ship] = []
 var _ship_spawn_transforms := {}
@@ -30,7 +31,8 @@ func _ready():
 	for child in get_children():
 		if child is Arena:
 			arena = child
-			break
+		elif child is HUDController:
+			hud = child
 	if not arena:
 		var path := _get_arena_scene_path()
 		if not path.is_empty():
@@ -99,6 +101,10 @@ func spawn_camera_rig(target: Ship) -> ShipCameraRig:
 	var rig: ShipCameraRig = CAMERA_RIG_SCENE.instantiate()
 	add_child(rig)
 	rig.target = target
+	# Also wires the scene's static HUD (if any) to the same ship, rather
+	# than letting it guess via the "ship" group.
+	if hud:
+		hud.ship = target
 	return rig