fix(multiplayer): enforce ranked tier enum

Game/scripts/ranked_profile_state.gd

@@ -29,7 +29,7 @@ func apply(payload: Dictionary) -> bool:
 	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 not _valid_nonnegative_integer(payload["ranked_games"]) or next_rating < 0.0 or next_rd < 0.0 or next_volatility < 0.0 or next_games < 0 or next_tier.is_empty():
+	if not is_finite(next_rating) or not is_finite(next_rd) or not is_finite(next_volatility) or not _valid_nonnegative_integer(payload["ranked_games"]) or next_rating < 0.0 or next_rd < 0.0 or next_volatility < 0.0 or next_games < 0 or not _valid_tier(next_tier):
 		return _reject("Profile response contains invalid values")
 	rating = next_rating
 	rd = next_rd
@@ -77,6 +77,10 @@ static func _valid_nonnegative_integer(value: Variant) -> bool:
 	return false
 
 
+static func _valid_tier(value: String) -> bool:
+	return value in ["PROVISIONAL", "BRONZE", "SILVER", "GOLD", "PLATINUM", "DIAMOND"]
+
+
 func set_error(reason: String) -> void:
 	available = false
 	error_message = reason

Game/tests/cases/test_control_plane_client.gd

@@ -157,6 +157,7 @@ func test_ranked_profile_is_backend_display_data_and_rejects_unsafe_values() ->
 	assert_true(not profile.apply({"rating": -1.0, "rd": 200.0, "volatility": 0.06, "ranked_games": 3, "tier": "GOLD", "provisional": false}), "negative rating is rejected")
 	assert_true(not profile.available, "unsafe response is not displayed")
 	assert_true(not profile.apply({"rating": 1500.0, "rd": 200.0, "volatility": 0.06, "ranked_games": 3, "tier": "", "provisional": false}), "empty tier is rejected")
+	assert_true(not profile.apply({"rating": 1500.0, "rd": 200.0, "volatility": 0.06, "ranked_games": 3, "tier": "MASTER", "provisional": false}), "unknown tier is rejected")
 	assert_true(not profile.apply({"rating": 1500.0, "rd": 200.0, "volatility": 0.06, "ranked_games": 3, "tier": "GOLD", "provisional": "false"}), "string boolean is rejected")
 	assert_true(not profile.apply({"rating": 1500.0, "rd": 200.0, "volatility": 0.06, "ranked_games": 3.5, "tier": "GOLD", "provisional": false}), "fractional ranked games is rejected")
 

multiplayer-next.md

@@ -1587,6 +1587,8 @@ Ticket timestamp normalization now preserves an invalid sentinel for malformed o
 
 Ranked profile projection now rejects fractional `ranked_games` values instead of silently truncating them, matching the OpenAPI integer contract.
 
+Ranked profile projection now enforces the OpenAPI tier enum, rejecting unknown tier labels before they reach the HUD.
+
 Signed MatchNet claims now also require exact JSON string/integer types for every identity, protocol, expiry, slot, team, and generation field; string-number coercion is rejected before canonical signature verification.
 
 Presentation progress: a shared `Game/themes/cosmic_clash_theme.tres` now gives the menu, lobby, matchmaking, and settings surfaces consistent button, input, option, and label styling. The custom-font portion of `TODO.md` remains open until a distributable font asset is selected.