Keep job table allocation, private synchronization callbacks, and
initialization-failure cleanup in one Rust adapter. The C wrapper now only
supplies pthread/object callbacks, preserving rounded capacity and the
destroy-before-custom-free ordering; table expansion reuses the same path.
Test Plan:
- rustfmt --check --edition 2021 rust/src/zstdmt_compress.rs
- git diff --check and git diff --cached --check
- Static inspection only; cargo, make, tests, fuzzers, and native/heavy
commands were not run under the global 40 GiB cap.
ddidderr
6c0bcced58