Reset temporal history, harden HDR sync, and optimize CausticaLOD IO

[KthanidKisure]

Summary

• reset DLSS Ray Reconstruction, ReSTIR, frame-generation, camera motion and animated-water temporal history together across ClientLevel swaps, >64-block one-frame teleports and long render discontinuities
• reset exposure on actual ClientLevel replacement so proxy/server world swaps cannot carry the previous world's adaptation state
• scope HDR-present transfer visibility to the actual HDR source image and remove the redundant global post-blit memory barrier
• move WynnLOD packed-session discovery/import kickoff to the warmed client tick so terrain workers only query already-published runtime state
• suppress duplicate same-tile .clod/.clodr reads and decompression across concurrent LOD workers with fixed striped load gates
• make WynnLOD/dependency downloads resumable with validated HTTP Range negotiation; interrupted known-length transfers retain .part data for the normal retry instead of restarting the ~592 MiB archive from byte 0
• reuse one HttpClient/connection pool for the one-time importer requests

Why

Wynncraft can replace a ClientLevel without changing dimension and can teleport the camera large distances. Old RR/ReSTIR/FG/motion history is invalid in both cases and otherwise appears as ghosting/smearing. CausticaLOD also had avoidable duplicate disk/decompression work when multiple workers missed the same tile at once, packed-source availability could perform session/import control work from worker threads, and any interrupted WynnLOD download discarded all progress.

Verification

• source patches generated with git diff --check
• branch is based on current main after merged PR Harden renderer reuse and streaming #24
• CI #217 on exact head 2fe2d5d31c6320babb3300774533fb0b5143db43: Windows NGX, Linux NGX, Java 25, Vulkan SDK 1.4.357 / Slang-SPIR-V, and bundled JAR all passed
• CI bundled artifact digest: sha256:4622f2cb04976a2d924ca0eb8b13fc97146e8bc6fe0cc2fa81f2a14b8da99e42
• runtime A/B packages are built only from that CI artifact: stable RR+FG 310.7.128, and experimental RR 310.7.128 + FG 310.8; all 433 entries match CI except the two intentional NVIDIA DLL replacements
• keep draft pending real Wynncraft first-import/teleport/RR/FG/HDR runtime validation