NsTut Endless

Endless 0.6

• Added Minecraft 1.21.1 support on Fabric and NeoForge and Minecraft 26.1.2 support on NeoForge while retaining the 1.20.1 Fabric/Forge line.
• Consolidated duplicated per-version implementation sources into shared 1.20.1/1.21.1, modern-renderer, and version-neutral source sets to reduce port drift.
• Added release packaging and metadata validation for every supported Minecraft/loader target, including version-specific unit-test coverage and exact-head CI checkout.
• Fixed NeoForge 26.1.2 high-Y rendering so the visibility Octree uses the exact moving ViewArea vertical window, including the full 32-section window while its 8-section rebase hysteresis is active.
• Added a live render-window regression at render distance 12 that verifies both ViewArea edges remain inside the visibility tree before and during the hysteresis hold.
• Fixed high-Y block entities such as chests remaining invisible after save/rejoin until player interaction or a neighboring block update. Sparse page synchronization now sends a fallback block-entity data packet after the authoritative sparse page when vanilla provides no custom update packet.
• Added same-JVM save/reopen coverage for chest, ender chest, and shulker-box block entities on NeoForge 26.1.2 and strengthened render assertions to use exact XYZ coordinates.
• Added config-gated high-Y block-entity/render diagnostics. debug defaults to false; when enabled, detailed ENDLESS_DEBUG traces are also written to logs/endless-debug.log.
• Fixed sparse block-entity render refresh ordering so delayed block entities are discovered and their render sections are rebuilt without relying on interaction.
• Kept the v0.5 sparse logical build envelope and fail-closed world-migration guarantees unchanged: supported configured Y remains -8,000,000 through 7,999,999.