[SirEdvin]

Summary

Add exact Minecraft 26.1.2 Fabric/NeoForge as two additional playable nodes, retaining 1.20.1 Fabric/Forge and 1.21.1 Fabric/NeoForge. Based on qualified rc.1 merge 48ca204bd18afce4e05820fddc2b5585ad49f321.

26.1.2 is for new worlds only. Cross-Minecraft-version world upgrades and downgrades are unsupported and untested. Same-version save/restart remains required. No release, merge, default-branch or repository-policy change is included.

• Native Java 25/Kotlin 2.4.0, unobfuscated Loom and exact public libraries 2.0.0-rc.1; existing Java 17/21 nodes retain Kotlin 2.0 language/API metadata and remapping.
• Server-owned global codec SavedData; registry-aware components and large digital item counts; native block inventory/update-tag callbacks; native exactly-once removal drops.
• Current registries, criteria, config, menus/screens, datagen, turtle/pocket serializers and data-driven turtle models. Public IDs and Lua/TypeScript contracts are unchanged.
• Native Testiarium/CCT on both targets; six-node build/GameTest/CI/artifact/docs integration, preserving canonical 1.20.1 sources and historical documentation routes/default.
• A small Java factory bridge preserves the native null vanilla-data-fixer contract on 1.21.1 under Kotlin 2.4 without warning suppressions.

See implementation brief and developer guide.

Verification

Local candidate evidence (complete redirected logs and report/hash receipts retained for the Kanban handoff):

• Clean nine-leaf / six-playable-node build, testMod compilation, publication metadata and packaged artifact audit: pass.
• Six-node native GameTests: 86/86; legacy 13/node, target 17/node, zero failures/errors/skips. Original limit/legacy/item/fluid/energy fixtures retained.
• Three target boundary cases (detached registry-aware inventory callbacks, actual inbound menu packet validation/transfers, native removal conservation) calibrated on both loaders: exactly the intended three sentinel cases fail, then the restored positive matrix passes.
• Target datagen: 38 JSON resources/loader, deterministic across repeat generation (76 identical hashes).
• TypeScript-to-Lua compilation, public API/documentation contracts, documentation tooling and workflow lint: pass.
• Both target loopback dedicated servers and physical clients: ready/join, six basic/advanced block/turtle/pocket Lua paths, authoritative transfers through both menus, reconnect/chunk reload with connection retained, and a copied same-version full-world restart preserving named/enchanted item data and digital timestamps/counts. Native processes shut down normally.
• Switch target/canonical back: 142 canonical/controller files byte-identical.

Final head 8e435cc5b31c94b9a86c10f46f88d07f365e3a11: all 16 literal-head checks (GitHub Actions app 15368) pass across both push and PR workflows. Downloaded native reports independently confirm 86/86; documentation checks pass. PR native/build run 40230180417, docs run 40230180425. Final-head local build, fresh six-node GameTests and all three docs fragments also pass. The downstream integration gate owns review and merge; no live Pages deployment is claimed.

The workflow-only follow-up installs Java 17/25/21 for Pages, keeping Java 21 last so historical Gradle wrappers still run. Implementation/runtime source hashes and all six local JAR bytes are unchanged from the tested implementation commit. Local/hosted JAR payloads match on all six nodes; five archives are byte-identical, while Fabric 26.1.2 differs only in ZIP OS/permission metadata. Distinct archive hashes are preserved rather than claiming byte-identical ZIP headers.

Boundaries

Private Xvfb/llvmpipe correctness smoke, not GPU/performance qualification. Offline authentication is restricted to loopback disposable test servers. No user worlds are accessed. Fluid/energy tests exercise the existing native consumer fixtures, rejection/partial admission and conservation, not every third-party transaction implementation.

The inherited Pages environment excludes multiversion; documentation generation/assembly are checked without changing deployment policy or claiming a live-site update.