feat(compress): move parameter update policy to Rust

Move ZSTD_isUpdateAuthorized behind the existing Rust parameter API while retaining the C context-stage checks, diagnostics, and mutation flow.

Test Plan:

- cargo test --manifest-path rust/Cargo.toml --no-default-features --features compression (187 tests)

- cargo clippy for library, benches, and tests

- make -B -C lib -j2 lib

rust/src/zstd_compress_params_api.rs

@@ -176,6 +176,26 @@ const C_MAX_BLOCK_SIZE: c_int = 1015;
 const C_REPCODE_RESOLUTION: c_int = 1016;
 const C_BLOCK_SPLITTER_LEVEL: c_int = 1017;
 
+#[inline]
+fn is_update_authorized(param: c_int) -> bool {
+    matches!(
+        param,
+        C_COMPRESSION_LEVEL
+            | C_HASH_LOG
+            | C_CHAIN_LOG
+            | C_SEARCH_LOG
+            | C_MIN_MATCH
+            | C_TARGET_LENGTH
+            | C_STRATEGY
+            | C_BLOCK_SPLITTER_LEVEL
+    )
+}
+
+#[no_mangle]
+pub extern "C" fn ZSTD_rust_isUpdateAuthorized(param: c_int) -> c_int {
+    is_update_authorized(param) as c_int
+}
+
 #[cfg(not(test))]
 unsafe extern "C" {
     fn ZSTD_rust_cctx_params_is_multithreaded() -> c_int;
@@ -974,6 +994,64 @@ mod tests {
     use std::mem::{align_of, offset_of, size_of, MaybeUninit};
     use std::sync::atomic::{AtomicUsize, Ordering};
 
+    #[test]
+    fn update_authorization_matches_the_c_parameter_policy() {
+        let authorized = [
+            C_COMPRESSION_LEVEL,
+            C_HASH_LOG,
+            C_CHAIN_LOG,
+            C_SEARCH_LOG,
+            C_MIN_MATCH,
+            C_TARGET_LENGTH,
+            C_STRATEGY,
+            C_BLOCK_SPLITTER_LEVEL,
+        ];
+        let unauthorized = [
+            C_FORMAT,
+            C_WINDOW_LOG,
+            C_CONTENT_SIZE_FLAG,
+            C_CHECKSUM_FLAG,
+            C_DICT_ID_FLAG,
+            C_FORCE_MAX_WINDOW,
+            C_NB_WORKERS,
+            C_JOB_SIZE,
+            C_OVERLAP_LOG,
+            C_RSYNCABLE,
+            C_ENABLE_DEDICATED_DICT_SEARCH,
+            C_ENABLE_LDM,
+            C_LDM_HASH_LOG,
+            C_LDM_MIN_MATCH,
+            C_LDM_BUCKET_SIZE_LOG,
+            C_LDM_HASH_RATE_LOG,
+            C_FORCE_ATTACH_DICT,
+            C_LITERAL_COMPRESSION_MODE,
+            C_TARGET_C_BLOCK_SIZE,
+            C_SRC_SIZE_HINT,
+            C_STABLE_IN_BUFFER,
+            C_STABLE_OUT_BUFFER,
+            C_BLOCK_DELIMITERS,
+            C_VALIDATE_SEQUENCES,
+            C_SPLIT_AFTER_SEQUENCES,
+            C_USE_ROW_MATCH_FINDER,
+            C_DETERMINISTIC_REF_PREFIX,
+            C_PREFETCH_CDICT_TABLES,
+            C_ENABLE_SEQ_PRODUCER_FALLBACK,
+            C_MAX_BLOCK_SIZE,
+            C_REPCODE_RESOLUTION,
+            -1,
+            1018,
+        ];
+
+        for param in authorized {
+            assert!(is_update_authorized(param));
+            assert_eq!(ZSTD_rust_isUpdateAuthorized(param), 1);
+        }
+        for param in unauthorized {
+            assert!(!is_update_authorized(param));
+            assert_eq!(ZSTD_rust_isUpdateAuthorized(param), 0);
+        }
+    }
+
     #[test]
     fn private_parameter_mirror_matches_the_c_layout() {
         let pointer_size = size_of::<usize>();