[Bugfix][Mamba] Clear deferred init metadata before speculative decode (#37165)

python/sglang/srt/managers/schedule_batch.py

@@ -3345,6 +3345,10 @@ class ScheduleBatch(ScheduleBatchDisaggregationDecodeMixin):
         # prefill-time tensor so it doesn't leak into ForwardBatch.
         self.input_embeds = None
 
+        self.mamba_cow_src_indices = None
+        self.mamba_cow_dst_indices = None
+        self.mamba_clear_indices = None
+
         # Clear context parallel metadata - CP is only for prefill, not decode
         if hasattr(self, "attn_cp_metadata") and self.attn_cp_metadata is not None:
             self.attn_cp_metadata = None