Fix GDScript editor warnings (shadowed vars, unused param, integer division)

Renames locals/params that shadowed base-class properties (Node.name,
Control.size, BoxContainer.alignment), prefixes an intentionally-unused
parameter, and annotates a deliberate integer division so the console
stays clean during development.

scripts/ui/flashcards_study.gd

@@ -597,7 +597,7 @@ func _refresh_deck_panel() -> void:
 	if deck_ring == null:
 		return
 	var dark := UIThemeService.is_dark_mode()
-	var name := "All decks"
+	var deck_name := "All decks"
 	var total := 0
 	var mastered := 0
 	var is_system := false
@@ -609,12 +609,12 @@ func _refresh_deck_panel() -> void:
 		for summary in decks:
 			var deck: Dictionary = summary.get("deck", {})
 			if str(deck.get("id", "")) == deck_id:
-				name = str(deck.get("name", "Deck"))
+				deck_name = str(deck.get("name", "Deck"))
 				total = int(summary.get("total", 0))
 				mastered = int(summary.get("mastered", 0))
 				is_system = bool(deck.get("isSystem", false))
 				break
-	deck_name_label.text = name
+	deck_name_label.text = deck_name
 	deck_system_badge.visible = is_system
 	var fraction := float(mastered) / float(total) if total > 0 else 0.0
 	deck_ring.configure(fraction, "%d%%" % roundi(fraction * 100.0), "Mastery", Brand.ROYAL_BLUE, dark)