Issue #32. `zit stat` gains full-form-bytes and delta-bytes, a partition of content-bytes. The counts alone mislead: a real history is 23% full-form by artifact and 84% by byte, because an artifact is stored whole exactly when delta did not pay.

tree_cache_bytes was 1 MiB, smaller than a wide tree's root fan-out, so nodes were evicted and re-decoded on the next commit that touched them. 64 MiB: byte-identical output, 67.4s to 56.5s importing 45,000 files. Unmeasurable below the old budget, which is why it went unnoticed.

fast_export.Limits.max_events loses its 1,000,000 default rather than gaining a new one. #29 removed that cap at the CLI and left it armed here; six callers silently re-inherited it, the benchmark among them.

test 3495/3495, fmt. check-in: 367539bec4 user: dmestas tags: sub-manifest