separate seqlock fine grain into separate index

bindings/cpp/include/svs/runtime/vamana_index.h

@@ -54,8 +54,11 @@ struct MemoryBreakdown {
     size_t graph_bytes = 0;
     size_t data_bytes = 0;
     size_t metadata_bytes = 0;
+    size_t reverse_edges_bytes = 0;
 
-    size_t total() const { return graph_bytes + data_bytes + metadata_bytes; }
+    size_t total() const {
+        return graph_bytes + data_bytes + metadata_bytes + reverse_edges_bytes;
+    }
 };
 
 // Abstract interface for Vamana-based indices.

bindings/cpp/src/vamana_index_impl.h

@@ -88,6 +88,7 @@ class VamanaIndexImpl {
         out.graph_bytes = breakdown.graph_bytes;
         out.data_bytes = breakdown.data_bytes;
         out.metadata_bytes = breakdown.metadata_bytes;
+        out.reverse_edges_bytes = breakdown.reverse_edges_bytes;
     }
 
     size_t dimensions() const { return dim_; }