Follow the GDScript style guide in every script

- Types on every parameter, return value and variable, and snake_case names
  (the player name limit is the constant MAX_NAME_LENGTH).
- Spelling fixes: *_triggered, character_selected, separator, caught_errors.
  The server's catched_errors key stays as the server sends it.
- Signals are connected with signal.connect() instead of by name.
- Code is ordered signals, constants, exported vars, vars, @onready vars,
  functions, with @onready on one line and two blank lines between functions.
- Every script starts with a ## description. Template comments, old LOC notes
  and commented-out code are gone, apart from the local play code.
- Lines are at most 100 characters, apart from the local play path.
- The screenshot tour turns off the blinking text cursor so pictures match.

tests/fakes/ui_tour.gd

@@ -87,6 +87,7 @@ static func prepare_autoloads() -> void:
 func run(on_state: Callable) -> void:
 	# The debug build lowers the winning score on startup; keep it out of reach
 	Settings.winning_score = 20
+	_stop_caret_blink(_main)
 	await _settle()
 	await on_state.call("startup", null)
 
@@ -194,6 +195,14 @@ func _call(method: String, args: Array = []) -> Variant:
 	return _main.callv(method, args)
 
 
+# A blinking text cursor would be shown in some pictures and not in others
+func _stop_caret_blink(node: Node) -> void:
+	if node is TextEdit || node is LineEdit:
+		node.caret_blink = false
+	for child: Node in node.get_children():
+		_stop_caret_blink(child)
+
+
 func _server() -> FakeHttpTransport:
 	return MusicServerClient.transport