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.

scroll_to_end_container.gd

@@ -1,9 +1,12 @@
 class_name ScrollToEndContainer
 extends ScrollContainer
+## A scroll container that scrolls to the end whenever its content grows, so the newest
+## item is always in view.
 
-var max_value = 0;
+var max_value: float = 0.0
 
-func _draw():
-	if max_value != self.get_v_scroll_bar().max_value:
-		max_value = self.get_v_scroll_bar().max_value
-		self.scroll_vertical = max_value
+
+func _draw() -> void:
+	if max_value != get_v_scroll_bar().max_value:
+		max_value = get_v_scroll_bar().max_value
+		scroll_vertical = int(max_value)