Cubic Reworked

Fixed

• Replaced the competing horizontal, surface, and volumetric streaming lanes with one global three-dimensional squared-distance order, matching vanilla's near-first chunk-streaming rule.
• Kept opposite equal-distance directions adjacent so initial loading remains spatially balanced around the player.
• Unified request selection, movement-time request retention, and asynchronous packet delivery under the same priority, preventing completed distant cubes from overtaking nearer pending cubes.
• Added stream-order regression coverage for initial loading, movement recentering, full-window traversal, and out-of-order asynchronous completions.