Phase 4 P4.1: persistent large-scene GPU visibility

[TrissTheBoss]

Status

DRAFT — DEV1 HOSTED-CI PACKAGE READY / REFERENCE RUNTIME REQUIRED / DO NOT MERGE.

Phase 3 is complete on synchronized main commit 01547b55f68690a5d0aac8405fc0fe91cdf440f9; post-merge Build #741 passed and no versioned release was published.

Frozen scope

P4.1 is a correctness-first shadow large-scene visibility milestone. It does not change the promoted P3.10 production draw path.

• Contract: ai/attempts/A-0203-phase4-p4.1-persistent-scene-gpu-visibility-contract.md
• Exact Minecraft 26.2 seam: ai/attempts/A-0204-phase4-p4.1-exact-mc26.2-large-scene-frustum-seam.md
• Dev1 package/runtime handoff: ai/attempts/A-0205-phase4-p4.1-dev1-ci-package-runtime-handoff.md

Implemented dev1 behavior

• bounded primitive persistent non-empty-section scene database with hard 2,500,000-slot ceiling;
• exact chunk load/unload and section empty/non-empty lifecycle observation;
• bounded overflow resync and changed-scene candidate snapshot construction;
• camera-relative real section AABBs;
• scalable Vulkan compute frustum classification and visible-identity compaction;
• explicit Synchronization2 transfer->compute and compute->readback edges;
• asynchronous completion-gated sampled readback;
• budgeted independent conservative CPU oracle;
• exact missing/unexpected/duplicate/false-cull accounting;
• camera-only frames do not rebuild/walk the full Java scene;
• P3.10 remains the sole production terrain replacement owner;
• native graphics ownership is unchanged.

No production GPU-driven draw ownership, indirect-count consumption, Hi-Z/temporal occlusion, async-compute ownership, LOD, translucency/fluids, mesher changes or P3.9 partial-remeshing revival is included.

Canonical dev1 package

Version: 0.4.0-phase4-dev1

Exact source/package authority:

fd58b9f2e915462f665b7d85f5d993456d5f930e

Hosted package CI:

• Build #757 / run 33653778087 — SUCCESS;
• Java 25 / Gradle 9.5.1 build — SUCCESS;
• artifact upload — SUCCESS;
• PR synthetic merge c6fa00d824beec44d5010103c38478306d2c0d43 has the exact same tree SHA ab82fd3908d174df668754c80ddec633da3bfb00 as the package-authority branch head.

Artifact ID 9855845429, wrapper digest sha256:b480c700f6b2b88ab1b0aa57136b43d55f9bd1d6d6fb99295f8abfbfc4f2ef9b.

Canonical runtime JAR:

• Obsidian-0.4.0-phase4-dev1.jar
• 493,377 bytes
• SHA-256 39c4bb4932bd6e7c00a4190c3514ef29eb926c337bba488f9a04bbef27120458

Reference runtime required

Exercise world entry/scene population, stable view, rapid 360-degree turns, horizontal chunk churn, vertical section traversal, ordinary edits, F3+T recovery, world leave/re-entry if practical, and normal shutdown.

Because P4.1 is shadow-only, the visual requirement is strict: the world must remain indistinguishable from the promoted P3.10 baseline.

Runtime promotion evidence must show real-scale candidates, one or more shadow visibility sample PASS records, zero missing/unexpected/duplicate identities, gpuFalseCullCount=0, no capacity failure, nonblocking readback/lifetime, cameraOnlyFullSceneScan=false, productionDrawOwnershipChanged=false, nativeGraphicsExpansion=false, inherited P3.10/P3.7/worker/lifetime gates clean, normal exit, and explicit human visual PASS.

Keep this PR DRAFT / DO NOT MERGE until those gates close.