Guard destructive settings and radio actions

- Route reset campaign and tutorial replay through one reusable confirmation dialog; repeated presses cannot stack or emit twice.
- Keep emergency hold-to-send single-shot and cover the post-submit release.
- Add destructive-action regression checks, strings and documentation.

src/game/ui/settings_panel.gd

@@ -32,6 +32,7 @@ var _reduce_motion: CheckButton = null
 var _captions: CheckButton = null
 var _bind_buttons := {}
 var _listening_action := ""
+var _destructive_dialog: ConfirmationDialog = null
 var settings: Dictionary = {}
 
 func _ready() -> void:
@@ -136,7 +137,7 @@ func _build() -> void:
 	var replay := Button.new()
 	replay.name = "ReplayTutorialButton"
 	replay.text = Strings.lookup("ui.settings_replay")
-	replay.pressed.connect(func(): replay_tutorial_requested.emit())
+	replay.pressed.connect(_confirm_replay_tutorial)
 	UiStyles.apply_button(replay, 16)
 	replay_row.add_child(replay)
 	var reset_campaign := Button.new()
@@ -284,15 +285,46 @@ func _on_difficulty_selected(index: int) -> void:
 	settings["ai_difficulty"] = ["easy", "normal", "hard"][clampi(index, 0, 2)]
 
 func _confirm_reset_campaign() -> void:
+	_open_destructive_dialog(Strings.lookup("ui.settings_reset_title"),
+		Strings.lookup("ui.settings_reset_confirm"),
+		func(): reset_campaign_requested.emit())
+
+func _confirm_replay_tutorial() -> void:
+	_open_destructive_dialog(Strings.lookup("ui.settings_replay_title"),
+		Strings.lookup("ui.settings_replay_confirm"),
+		func(): replay_tutorial_requested.emit())
+
+## One modal at a time; a second press while it is open focuses the existing
+## dialog instead of creating another one (and possibly emitting twice).
+func _open_destructive_dialog(title: String, body: String, callback: Callable) -> void:
+	if _destructive_dialog != null and is_instance_valid(_destructive_dialog):
+		# Reuse the open confirmation instead of stacking a second one. The
+		# dialog is dismissed on confirm/cancel, so an existing instance is
+		# always the one waiting for the player's decision.
+		if _destructive_dialog.is_inside_tree():
+			_destructive_dialog.grab_focus()
+		return
 	var dialog := ConfirmationDialog.new()
-	dialog.title = "Reset campaign"
-	dialog.dialog_text = Strings.lookup("ui.settings_reset_confirm")
-	dialog.confirmed.connect(func(): reset_campaign_requested.emit())
+	_destructive_dialog = dialog
+	dialog.title = title
+	dialog.dialog_text = body
+	dialog.confirmed.connect(func():
+		if _destructive_dialog != dialog:
+			return
+		_dismiss_destructive_dialog(dialog)
+		callback.call())
+	dialog.canceled.connect(func(): _dismiss_destructive_dialog(dialog))
 	add_child(dialog)
 	UiStyles.apply_button(dialog.get_ok_button(), 16)
 	UiStyles.apply_button(dialog.get_cancel_button(), 16)
 	dialog.popup_centered()
-	dialog.confirmed.connect(dialog.queue_free)
+
+func _dismiss_destructive_dialog(dialog: ConfirmationDialog) -> void:
+	if _destructive_dialog == dialog:
+		_destructive_dialog = null
+	if is_instance_valid(dialog):
+		dialog.hide()
+		dialog.queue_free()
 
 func _refresh_bind_buttons() -> void:
 	var remaps: Dictionary = settings.get("input_bindings", {})