Move LDM block-compressor strategy validation, selection ordering, and callback error propagation into Rust while retaining dictionary-mode lookup, MatchState mutation, and the actual codec callback in C. Invalid preflight inputs now use the existing generic error path, and valid strategies preserve the original optimal-parser boundary.
Test Plan: ulimit -v 41943040; CARGO_BUILD_JOBS=1 cargo clippy --manifest-path rust/Cargo.toml --all-targets -- -D warnings; cargo +nightly fmt --manifest-path rust/Cargo.toml --all -- --check; make -j1; ./tests/rustLibSmoke; make -j1 -C tests test (all shell tests, large streaming tests, native tester, fuzzer phases, and zstream tester passed).