feat(*): Add 3-2-1 kickoff countdown before play and after goals

Game/scripts/HUDController.gd

@@ -9,6 +9,7 @@ class_name HUDController
 @onready var score_row = get_node_or_null("Control/ScoreRow")
 @onready var team0_score_label = get_node_or_null("Control/ScoreRow/Team0Score")
 @onready var team1_score_label = get_node_or_null("Control/ScoreRow/Team1Score")
+@onready var kickoff_label = get_node_or_null("Control/KickoffLabel")
 @onready var result_overlay = get_node_or_null("Control/ResultOverlay")
 @onready var result_label = get_node_or_null("Control/ResultOverlay/Center/VBox/ResultLabel")
 @onready var final_score_label = get_node_or_null("Control/ResultOverlay/Center/VBox/FinalScoreLabel")
@@ -72,6 +73,9 @@ func _initialize_hud():
 	if game_manager and game_manager.has_signal("match_ended"):
 		game_manager.match_ended.connect(_on_match_ended)
 
+	if game_manager and game_manager.has_signal("kickoff_countdown"):
+		game_manager.kickoff_countdown.connect(_on_kickoff_countdown)
+
 func _connect_ship_signals():
 	# Route ship telemetry to the flight instruments
 	if ship.has_signal("speed_changed"):
@@ -127,6 +131,13 @@ func _on_score_changed(score: Dictionary):
 	if team1_score_label and is_instance_valid(team1_score_label):
 		team1_score_label.text = str(score.get(1, 0))
 
+func _on_kickoff_countdown(count: int):
+	if not kickoff_label or not is_instance_valid(kickoff_label):
+		return
+	kickoff_label.visible = count > 0
+	if count > 0:
+		kickoff_label.text = str(count)
+
 func _on_match_ended(winning_team: int, score: Dictionary):
 	if not result_overlay or not is_instance_valid(result_overlay):
 		return

Game/scripts/match_mode.gd

@@ -9,9 +9,12 @@ signal timer_updated(minutes: int, seconds: int)
 signal score_changed(score: Dictionary)
 # winning_team is -1 for a draw.
 signal match_ended(winning_team: int, score: Dictionary)
+# Counts 3, 2, 1, then 0 ("go", hide the label).
+signal kickoff_countdown(count: int)
 
 # How long the result overlay stays up before returning to the menu.
 const RESULT_SCREEN_SECONDS := 5.0
+const KICKOFF_COUNTDOWN_SECONDS := 3
 
 @export var match_length_seconds := 150.0
 
@@ -32,6 +35,8 @@ func _start() -> void:
 	spawn_camera_rig(player_ship)
 	spawn_ship(1, 0, _make_opponent_controller())
 
+	await _run_kickoff_countdown()
+
 	match_timer = Timer.new()
 	match_timer.one_shot = true
 	match_timer.wait_time = match_length_seconds
@@ -66,8 +71,34 @@ func _on_goal_scored(conceding_team: int) -> void:
 	score[scoring_team] += 1
 	score_changed.emit(score.duplicate())
 	print("Goal for team %d! Score: %d - %d" % [scoring_team, score[0], score[1]])
+	await _run_kickoff_countdown()
+
+
+# Used both for the initial kickoff and after every goal. Freezes ball/ships
+# via RigidBody3D.freeze — a built-in engine property — so this needs zero
+# changes to ship.gd/ball.gd/ship_controller.gd, keeping training_mode.gd
+# (which never calls into this file) completely untouched.
+func _run_kickoff_countdown() -> void:
 	reset_ball()
 	reset_ships()
+	_set_frozen(true)
+	for count in range(KICKOFF_COUNTDOWN_SECONDS, 0, -1):
+		kickoff_countdown.emit(count)
+		# process_always=false: if full-time fires mid-countdown (see
+		# _on_match_timer_timeout's get_tree().paused = true), this stalls
+		# harmlessly in lockstep with the pause instead of ticking a
+		# countdown label over the results screen.
+		await get_tree().create_timer(1.0, false).timeout
+	kickoff_countdown.emit(0)
+	_set_frozen(false)
+
+
+func _set_frozen(frozen: bool) -> void:
+	if is_instance_valid(ball):
+		ball.set_deferred("freeze", frozen)
+	for ship in ships:
+		if is_instance_valid(ship):
+			ship.set_deferred("freeze", frozen)
 
 
 func _on_match_timer_timeout() -> void: