Remove the sequence-compression API's C frame-header callback and carry the
validated frame parameters as scalar state. Rust now serializes headers for
both sequence API variants through the same frame-header leaf, while C keeps
only CCtx initialization and checksum callbacks behind the boundary.
Test Plan:
- ulimit -v 41943040; CARGO_BUILD_JOBS=1 cargo test --lib zstd_compress::tests::sequence_api -- --nocapture
- ulimit -v 41943040; CARGO_BUILD_JOBS=1 cargo clippy --all-targets -- -D warnings
- ulimit -v 41943040; CARGO_BUILD_JOBS=1 cargo test
- ulimit -v 41943040; make -j1
- ulimit -v 41943040; make -j1 -C tests test-zstream ZSTREAM_TESTTIME=-T2s
- ulimit -v 41943040; make -j1 -C tests test-fuzzer FUZZERTEST=-T3s FUZZER_FLAGS=--no-big-tests
ddidderr
4a8345f596