feat(compress): call the Rust CCtx block reset leaf directly

Pass the private CCtx compressed-block-state pointer into the Rust reset
tail and invoke the existing Rust reset leaf directly. Remove the
redundant C adapter while keeping reset-tail ordering and private state
opaque at the ABI boundary.

Strengthen reset-tail tests to verify the direct reset state.

Test Plan:
- ulimit -v 41943040 && CARGO_BUILD_JOBS=1 cargo test --manifest-path rust/Cargo.toml
- ulimit -v 41943040 && CARGO_BUILD_JOBS=1 cargo clippy --manifest-path rust/Cargo.toml --all-targets -- -D warnings
- 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
- ulimit -v 41943040 && cargo fmt --manifest-path rust/Cargo.toml -- --check
- git diff --check

lib/compress/zstd_compress.c

@@ -1563,14 +1563,14 @@ typedef char ZSTD_rust_reset_cctx_workspace_state_layout[
 typedef struct {
     void* callbackContext;
     ZSTD_rust_resetCCtxStorageCallback_f initialize;
-    ZSTD_rust_resetCCtxStorageCallback_f resetCompressedBlockState;
+    void* compressedBlockState;
     ZSTD_rust_resetCCtxTailCallback_f resetMatchState;
     ZSTD_rust_resetCCtxTailCallback_f resetStorage;
 } ZSTD_rust_resetCCtxTailState;
 typedef char ZSTD_rust_reset_cctx_tail_state_layout[
         (offsetof(ZSTD_rust_resetCCtxTailState, callbackContext) == 0
          && offsetof(ZSTD_rust_resetCCtxTailState, initialize) == sizeof(void*)
-         && offsetof(ZSTD_rust_resetCCtxTailState, resetCompressedBlockState)
+         && offsetof(ZSTD_rust_resetCCtxTailState, compressedBlockState)
                 == 2 * sizeof(void*)
          && offsetof(ZSTD_rust_resetCCtxTailState, resetMatchState)
                 == 3 * sizeof(void*)
@@ -4248,13 +4248,6 @@ static void ZSTD_rust_resetCCtxTail_initialize(void* opaque)
     cctx->dictContentSize = 0;
 }
 
-static void ZSTD_rust_resetCCtxTail_resetCompressedBlockState(void* opaque)
-{
-    ZSTD_rust_resetCCtxTailContext* const context =
-            (ZSTD_rust_resetCCtxTailContext*)opaque;
-    ZSTD_reset_compressedBlockState(context->cctx->blockState.prevCBlock);
-}
-
 static size_t ZSTD_rust_resetCCtxTail_resetMatchState(void* opaque)
 {
     ZSTD_rust_resetCCtxTailContext* const context =
@@ -4427,8 +4420,7 @@ static size_t ZSTD_resetCCtx_internal(ZSTD_CCtx* zc,
             tailContext.storageState = &storageState;
             tailState.callbackContext = &tailContext;
             tailState.initialize = ZSTD_rust_resetCCtxTail_initialize;
-            tailState.resetCompressedBlockState =
-                    ZSTD_rust_resetCCtxTail_resetCompressedBlockState;
+            tailState.compressedBlockState = zc->blockState.prevCBlock;
             tailState.resetMatchState = ZSTD_rust_resetCCtxTail_resetMatchState;
             tailState.resetStorage = ZSTD_rust_resetCCtxTail_resetStorage;
             FORWARD_IF_ERROR(ZSTD_rust_resetCCtxTail(&tailState), "");