feat(compress): move dictionary attachment predicate to Rust

Keep the private CDict and CCtx parameter layouts in C while passing only the
five scalar inputs needed by the dictionary-attachment heuristic. Rust now
owns the exact per-strategy cutoffs and preserves unknown-size handling,
dedicated-search short-circuiting, force-attach and force-copy precedence, and
the force-window prohibition. The existing C helper and reset/copy call paths
remain unchanged.

Test Plan:
- `cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression dictionary_attachment` -- passed (2 tests)
- `make -B -C lib -j2 lib` -- passed
- `make -C tests -j2 fuzzer` -- passed
- `./tests/fuzzer -s4560 -t47 -i48 -v` -- passed
- Rust clippy for the library, benches, and tests before and after nightly formatting -- passed
- `cargo +nightly fmt --manifest-path rust/Cargo.toml` -- passed
- `git diff --cached --check` -- passed

lib/compress/zstd_compress.c

@@ -124,6 +124,9 @@ int ZSTD_rust_params_cdictIndicesAreTagged(ZSTD_compressionParameters cParams);
 int ZSTD_rust_params_dedicatedDictSearchIsSupported(ZSTD_compressionParameters cParams);
 U32 ZSTD_rust_params_dedicatedDictSearch_getHashLog(U32 hashLog);
 U32 ZSTD_rust_params_dedicatedDictSearch_revertHashLog(U32 hashLog);
+int ZSTD_rust_params_shouldAttachDict(int strategy, int dedicatedDictSearch,
+                                      U64 pledgedSrcSize, int attachDictPref,
+                                      int forceWindow);
 
 /* CCtx parameter state is mirrored by rust/src/zstd_compress_params_api.rs.
  * Rust owns parameter bounds and clamping; C exposes only the
@@ -1786,36 +1789,16 @@ void ZSTD_invalidateRepCodes(ZSTD_CCtx* cctx) {
     assert(!ZSTD_window_hasExtDict(cctx->blockState.matchState.window));
 }
 
-/* These are the approximate sizes for each strategy past which copying the
- * dictionary tables into the working context is faster than using them
- * in-place.
- */
-static const size_t attachDictSizeCutoffs[ZSTD_STRATEGY_MAX+1] = {
-    8 KB,  /* unused */
-    8 KB,  /* ZSTD_fast */
-    16 KB, /* ZSTD_dfast */
-    32 KB, /* ZSTD_greedy */
-    32 KB, /* ZSTD_lazy */
-    32 KB, /* ZSTD_lazy2 */
-    32 KB, /* ZSTD_btlazy2 */
-    32 KB, /* ZSTD_btopt */
-    8 KB,  /* ZSTD_btultra */
-    8 KB   /* ZSTD_btultra2 */
-};
-
 static int ZSTD_shouldAttachDict(const ZSTD_CDict* cdict,
                                  const ZSTD_CCtx_params* params,
                                  U64 pledgedSrcSize)
 {
-    size_t cutoff = attachDictSizeCutoffs[cdict->matchState.cParams.strategy];
-    int const dedicatedDictSearch = cdict->matchState.dedicatedDictSearch;
-    return dedicatedDictSearch
-        || ( ( pledgedSrcSize <= cutoff
-            || pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN
-            || params->attachDictPref == ZSTD_dictForceAttach )
-          && params->attachDictPref != ZSTD_dictForceCopy
-          && !params->forceWindow ); /* dictMatchState isn't correctly
-                                      * handled in _enforceMaxDist */
+    return ZSTD_rust_params_shouldAttachDict(
+            cdict->matchState.cParams.strategy,
+            cdict->matchState.dedicatedDictSearch,
+            pledgedSrcSize,
+            (int)params->attachDictPref,
+            params->forceWindow);
 }
 
 static size_t