feat: display backend ranked profile

Game/scripts/ranked_profile_state.gd

@@ -0,0 +1,60 @@
+class_name RankedProfileState
+extends RefCounted
+
+# Read-only server projection. The client deliberately stores no tier bands
+# or rating formula: it displays the backend's committed view verbatim after
+# validating the shape and numeric safety of the response.
+
+var available := false
+var rating := 0.0
+var rd := 0.0
+var volatility := 0.0
+var ranked_games := 0
+var tier := ""
+var provisional := false
+var season_id := ""
+var error_message := ""
+
+
+func apply(payload: Dictionary) -> bool:
+	var required := ["rating", "rd", "volatility", "ranked_games", "tier", "provisional"]
+	for key in required:
+		if not payload.has(key):
+			return _reject("Profile response is missing " + key)
+	if not (payload["rating"] is int or payload["rating"] is float) or not (payload["rd"] is int or payload["rd"] is float) or not (payload["volatility"] is int or payload["volatility"] is float) or not payload["ranked_games"] is int or not payload["tier"] is String or not payload["provisional"] is bool:
+		return _reject("Profile response contains invalid types")
+	var next_rating := float(payload["rating"])
+	var next_rd := float(payload["rd"])
+	var next_volatility := float(payload["volatility"])
+	var next_games := int(payload["ranked_games"])
+	var next_tier := String(payload["tier"])
+	if not is_finite(next_rating) or not is_finite(next_rd) or not is_finite(next_volatility) or next_rating < 0.0 or next_rd < 0.0 or next_volatility < 0.0 or next_games < 0 or next_tier.is_empty():
+		return _reject("Profile response contains invalid values")
+	rating = next_rating
+	rd = next_rd
+	volatility = next_volatility
+	ranked_games = next_games
+	tier = next_tier
+	provisional = bool(payload["provisional"])
+	season_id = String(payload.get("season_id", ""))
+	available = true
+	error_message = ""
+	return true
+
+
+func set_error(reason: String) -> void:
+	available = false
+	error_message = reason
+
+
+func display_text() -> String:
+	if not available:
+		return error_message if not error_message.is_empty() else "Ranked profile unavailable"
+	var status := "Provisional" if provisional else tier
+	return "%s · %d ranked game%s" % [status, ranked_games, "" if ranked_games == 1 else "s"]
+
+
+func _reject(reason: String) -> bool:
+	available = false
+	error_message = reason
+	return false