feat: add basic UI scenes (card, hand, training room, main menu)

src/ui/scenes/training_room.gd

@@ -0,0 +1,70 @@
+extends Control
+
+var controller: TrainingController
+
+@onready var hand_area: Node = $HandArea
+@onready var play_button: Button = $Buttons/PlayButton
+@onready var pass_button: Button = $Buttons/PassButton
+@onready var hint_button: Button = $Buttons/HintButton
+@onready var status_label: Label = $StatusLabel
+
+func _ready() -> void:
+	hand_area.training_controller = controller
+	play_button.pressed.connect(_on_play_pressed)
+	pass_button.pressed.connect(_on_pass_pressed)
+	hint_button.pressed.connect(_on_hint_pressed)
+
+func start_training() -> void:
+	controller = TrainingController.new()
+	controller.start_game(Config.rule_config, 0)
+	controller.turn_ready.connect(_on_turn_ready)
+	controller.state_changed.connect(_refresh_ui)
+	controller.game_ended.connect(_on_game_ended)
+	_refresh_ui()
+
+func _on_turn_ready(player_idx: int, is_human: bool) -> void:
+	if is_human:
+		hand_area.enable_input()
+		status_label.text = "你的回合"
+	else:
+		hand_area.disable_input()
+		status_label.text = "%s 思考中..." % controller.game_state.player_names[player_idx]
+
+func _on_play_pressed() -> void:
+	var selected := hand_area.selected_cards
+	if selected.is_empty():
+		return
+	var result := controller.handle_human_play(selected)
+	if not result.ok:
+		status_label.text = "无效出牌"
+		return
+	hand_area.clear_selection()
+	_refresh_ui()
+
+func _on_pass_pressed() -> void:
+	var result := controller.handle_human_pass()
+	if not result.ok:
+		status_label.text = "不能过牌"
+		return
+	_refresh_ui()
+
+func _on_hint_pressed() -> void:
+	var hint := controller.get_hint()
+	if hint == null or hint.type == -1:
+		status_label.text = "建议：过牌"
+		return
+	hand_area.clear_selection()
+	for card in hint.cards:
+		for cn in hand_area.card_nodes:
+			if cn.card_data != null and cn.card_data.card_id == card.card_id:
+				cn.set_selected(true)
+				hand_area.selected_cards.append(card)
+	status_label.text = "建议牌型: %s (rank=%d)" % [hint.type, hint.primary_rank]
+
+func _on_game_ended(winner_team: int, reason: String) -> void:
+	status_label.text = "游戏结束! 队伍 %d 获胜" % winner_team
+	hand_area.disable_input()
+
+func _refresh_ui() -> void:
+	if controller and controller.game_state:
+		hand_area.update_hand(controller.game_state.get_hand(0))