Weavatrix Git 0.1.1

Direct in-process competitor benchmark release. Adds round-robin exact-parity comparison with gix 0.86 and libgit2 1.9 via git2 0.21, optimized bounded first-parent history, zero-copy shared object snapshots, auto-refreshing shared index snapshots, 10,000-path index fixtures, machine-readable benchmark results, and CI parity runs on Windows and Ubuntu. The published crate remains safe Rust, dependency-free, and MIT licensed.