facebook/zstd v1.5.7 and Cyan4973/xxHash v0.8.3 pinned by url+hash in build.zig.zon and compiled in build.zig (ZSTD_DISABLE_ASM for -Dtarget portability, XXH_NAMESPACE=ZSTD_ so zstd's bundled xxhash can't collide with the standalone one). replaces the homebrew library-path hack; verified: native tests green AND zig build -Dtarget=x86_64-linux-gnu compiles — the deploy target no longer depends on host paths. also unblocks segment sealing: xxh3-128 (required by gloom bloom wire format) now bound from the canonical xxHash and verified against independently generated vectors (python xxhash). Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>