Move the public CStream reset wrapper's pledge normalization, callback order,
and error short-circuiting into Rust. Keep the C-owned context reset and
pledged-size mutation behind opaque callbacks with an explicit ABI projection.
Test Plan:
- ulimit -v 41943040; CARGO_BUILD_JOBS=1 cargo test --manifest-path rust/Cargo.toml reset_cstream -- --test-threads=1
- ulimit -v 41943040; make -B -C programs -j1 zstd
- git diff --cached --check