style(ann): iterate levels directly in the batch entry-point update (clippy)

Co-Authored-By: Claude Fable 5.1 <[email protected]>

crates/clawhdf5-ann/src/hnsw.rs

@@ -296,10 +296,10 @@ impl HnswIndex {
             }
             prune_overflowed(vectors, &mut graph, overflowed, (m, m_max0), metric);
 
-            for i in next..end {
+            for (i, &level) in node_levels.iter().enumerate().take(end).skip(next) {
-                if node_levels[i] > ep_level {
+                if level > ep_level {
                     entry_point = i;
-                    ep_level = node_levels[i];
+                    ep_level = level;
                 }
             }
             next = end;