Release Notes for 477

Luau Types: In strict mode, operator 'or' no longer resolves to an optional type when only the left-hand-side of the operator is an optional.

Optimized raycasts for 2x speedups in complex maps.

When resetting the primary CFrame of a model in games, its LOD gets transformed too without re-computing its model mesh.

The type of assert now correctly contains the optional second argument.

Added automatic centering for lines navigated to in the Script Editor.

Toolbox item background now defaults to matching the current theme.

Luau: Type guards can now be used in conjunction with other constraints, i.e. type(foo) == "Instance" and foo:IsA("Part").

Added new method to find a descendent of an instance using breadth-first search

"Root" and "HumanoidRootNode" joints were silently ignored for R15 imports, causing developer confusion.

Fixed the proximityPrompt icon

Fixed DialogChoices causing the player to get stuck when using a gamepad

This fixes an old math error for the under water fog appearance that was happening when setting Terrain/WaterTransparency to 0 affecting a subset of CPUs.