release: prepare v0.2.1 cross-platform performance update - #3

Summary

• ship the latest measured Steam Deck performance configuration, including exact adjacent texture descriptor-set reuse
• make ordinary SteamOS launches avoid an accidentally attached system RenderDoc library, matching the no-debugger path used for performance measurements
• restore a complete self-contained Apple Silicon archive with Vulkan loader and MoltenVK
• retain every existing executable name while adding one first-run Project8Recomp wrapper
• improve setup, recovery, settings, save/log folder access, issue-reporting guidance, and user-facing wording
• keep Windows experimental while mitigating the reported timer and pacing failure

Exact release-candidate verification

• Linux archive on Steam Deck, marked 2,667-draw Funpark view: 24.996 ms mean, 24.998 ms p50, 27.003 ms p95, 40.01 effective FPS, 257.6% process CPU
• Windows archive through Proton 10 on Steam Deck: all nine visual checkpoints; player-default pacing 33.31 / 34.49 ms p50 / p95; uncapped 27.83 / 32.02 ms and 35.64 effective FPS
• macOS archive on a 2020 Apple M1 MacBook Pro: self-contained Vulkan path, all nine checkpoints, complete 2,704-draw view; severe-scene caveat documented at 4.22 effective FPS

Proton validates the archive, launcher handoff, Vulkan path, scene loading, and pacing through a compatibility layer. It does not replace testing on real Windows hardware, so issue #1 remains open and is described as mitigated rather than fixed. Issue #2 was resolved in v0.2.0 and remains covered by launcher argument tests.

Gates

• all three hosted launcher jobs pass at the candidate commit
• 37-patch SDK series applies from the pinned pristine base
• launcher tests and strict UI document loading pass
• complete archives include checksums and required runtime components
• Linux ABI floor, runtime dependency boundary, source-content boundary, and stripped build-path checks pass
• Linux player entry points use the no-debugger SteamOS path by default; developers can explicitly opt into RenderDoc