Add ClientWorldOrigin and automatic floating-origin shift in ChunkManager

[ArtifactForms]

Motivation

• Prevent floating-point precision issues in client-side rendering by rebasing local coordinates around a movable origin chunk.
• Allow the client to keep rendering and local calculations numerically stable while the server continues to use absolute coordinates.

Description

• Introduces a new ClientWorldOrigin class that stores an origin chunk, converts between absolute and local world coordinates, and exposes isOutsideShiftThreshold to detect when to rebase.
• Adds a ClientWorld.origin instance and exposes it via ClientWorld.getOrigin().
• Integrates origin usage into ChunkManager: the manager now retrieves the origin from the world, checks isOutsideShiftThreshold each update, and calls setOriginChunk when the player moves past a configurable threshold; also adds originShiftThresholdChunks with getter/setter and a default constant.
• Exposes the world origin from the client via GameClient.getWorldOrigin() to allow other systems to query local/absolute transforms.

Testing

• Built the project to verify compilation and integration using ./gradlew build, and the build completed successfully.
• Ran the project's automated test task using ./gradlew test, and the existing test suite completed without failures.

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Codex Task