Integrate DS4 execution parity in Rust

src/engine/metal/checkpoint.rs

@@ -301,6 +301,15 @@ impl DeepSeekExecutor {
         self.tokens = tokens;
         self.logits = logits;
         self.checkpoint_tag = checkpoint_tag;
+        if let Some(mtp) = &mut self.legacy_mtp {
+            mtp.draft_token = None;
+            mtp.raw_rows = 0;
+        }
+        if let Some(dspark) = &mut self.dspark {
+            dspark.capture_mask = 0;
+            dspark.cache_start = 0;
+            dspark.cache_len = 0;
+        }
         Ok(())
     }
 }