fix(client): address PR #86 review — archetype validation, teleport clear, ticker layout

- protocol.gd: replace capitalize() with explicit match for archetype
  string mapping, push_error on unknown input with Detective fallback
- main.gd: clear _known_triangle_ids in _teleport_transition() alongside
  _known_recognition_ids so chime re-fires after room change
- news_ticker.gd: defer get_minimum_size() via call_deferred to run
  after layout pass, fixing first-frame scroll distance
- 3 new tests: unknown archetype fallback, triangle dedup per-id,
  independent triangle ID firing

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

client/ui/news_ticker.gd

@@ -36,12 +36,19 @@ func update_from_state() -> void:
 	if new_text != _text:
 		_text = new_text
 		_label.text = _text
-		# Reset scroll to start from the right edge on new headline.
-		_content_width = _label.get_minimum_size().x
+		# Reset scroll to start from right edge on new headline.
+		# Defer width read by one frame: get_minimum_size() returns stale
+		# data if called before the layout pass that follows text assignment.
 		_scroll_x = size.x
+		_content_width = 0.0  # will be updated after layout in _process
+		call_deferred("_update_content_width")
 	visible = true
 
 
+func _update_content_width() -> void:
+	_content_width = _label.get_minimum_size().x
+
+
 func _process(delta: float) -> void:
 	if not visible:
 		return