refactor(mt): move serial reset error policy to Rust

Project the private serial-state reset result into Rust for the stream-initialization error decision while retaining C-owned allocation, serial-state mutation, dictionary setup, synchronization, callback order, and ABI layouts. Nonzero callback status preserves the existing memory_allocation error path.

Test Plan: ulimit -v 41943040; CARGO_BUILD_JOBS=1 cargo clippy --manifest-path rust/Cargo.toml --all-targets -- -D warnings; cargo clippy --manifest-path rust/cli/Cargo.toml --all-targets -- -D warnings; cargo test --manifest-path rust/cli/Cargo.toml --all-targets (188 passed); 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).

lib/compress/zstdmt_compress.c

@@ -853,6 +853,7 @@ size_t ZSTDMT_rust_initCStream(
         ZSTDMT_initResetStreamFn resetStream,
         ZSTDMT_initDictionaryFn updateDictionary,
         ZSTDMT_initSerialResetFn serialReset);
+size_t ZSTDMT_rust_initSerialResetResult(int status);
 typedef void (*ZSTDMT_resetStreamCallbackFn)(void* opaque);
 typedef struct {
     void* callbackContext;
@@ -2779,12 +2780,10 @@ static size_t ZSTDMT_initCStreamUpdateDictionary(void* opaque)
 static size_t ZSTDMT_initCStreamSerialReset(void* opaque, size_t targetSectionSize)
 {
     ZSTDMT_initCStreamState* const state = (ZSTDMT_initCStreamState*)opaque;
-    if (ZSTDMT_serialState_reset(
+    return ZSTDMT_rust_initSerialResetResult(ZSTDMT_serialState_reset(
             &state->mtctx->serial, state->mtctx->seqPool, state->params,
             targetSectionSize, state->dict, state->dictSize,
-            state->dictContentType))
-        return ERROR(memory_allocation);
-    return 0;
+            state->dictContentType));
 }
 
 /* ====================================== */