fix(ui): remove Node2D cursor_renderer from Control-typed HudGroups array

CursorRenderer extends Node2D, not Control — can't be registered in
HudGroups. Removed from gameplay group. Also dropped typed array
annotation to avoid runtime type mismatch errors.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

client/scripts/main.gd

@@ -64,10 +64,10 @@ func _ready() -> void:
 
 	# D-170: Register HUD nodes into visibility groups
 	# Gameplay group — hidden when implant panels are open
-	for node: Control in [hud, minimap, stance_indicator, cursor_renderer,
+	for node in [hud, minimap, stance_indicator,
 			interaction_prompt, interaction_list, inventory_grid, news_ticker,
 			examine_display, world_radial]:
-		if node:
+		if node and node is Control:
 			HudGroups.register(node, "gameplay")
 
 	# #775: Initialize extracted components