feat(compress): port the public one-shot compressor to Rust

Implement ZSTD_compress in Rust using the migrated parameter, match-finder,
sequence, frame, and superblock leaves. Keep the private context and streaming
entry points C-backed until their configuration-dependent context projection is
ported, and remove only the duplicate C one-shot definition.

Test Plan:
- cargo test --manifest-path rust/Cargo.toml
- cargo clippy --manifest-path rust/Cargo.toml --all-targets -- -D warnings
- cargo +nightly fmt --manifest-path rust/Cargo.toml --all -- --check
- make -B -C tests test-rust-lib-smoke V=1
- git diff --check

Refs: rust/src/zstd_compress.rs, lib/compress/zstd_compress.c

lib/compress/zstd_compress.c

@@ -4776,24 +4776,7 @@ size_t ZSTD_compressCCtx(ZSTD_CCtx* cctx,
     return ZSTD_compress_usingDict(cctx, dst, dstCapacity, src, srcSize, NULL, 0, compressionLevel);
 }
 
-size_t ZSTD_compress(void* dst, size_t dstCapacity,
-               const void* src, size_t srcSize,
-                     int compressionLevel)
-{
-    size_t result;
-#if ZSTD_COMPRESS_HEAPMODE
-    ZSTD_CCtx* cctx = ZSTD_createCCtx();
-    RETURN_ERROR_IF(!cctx, memory_allocation, "ZSTD_createCCtx failed");
-    result = ZSTD_compressCCtx(cctx, dst, dstCapacity, src, srcSize, compressionLevel);
-    ZSTD_freeCCtx(cctx);
-#else
-    ZSTD_CCtx ctxBody;
-    ZSTD_initCCtx(&ctxBody, ZSTD_defaultCMem);
-    result = ZSTD_compressCCtx(&ctxBody, dst, dstCapacity, src, srcSize, compressionLevel);
-    ZSTD_freeCCtxContent(&ctxBody);   /* can't free ctxBody itself, as it's on stack; free only heap content */
-#endif
-    return result;
-}
+/* ZSTD_compress() is implemented by rust/src/zstd_compress.rs. */
 
 
 /* =====  Dictionary API  ===== */