Add missing cstdint include for gcc-13 compatibility

gcc-13 is stricter about header includes - uint64_t now requires
explicit <cstdint> include as it is no longer transitively included.

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: lums658

include/nwgraph/adaptors/dag_range.hpp

@@ -20,6 +20,7 @@
 #ifndef NW_GRAPH_DAG_RANGE_HPP
 #define NW_GRAPH_DAG_RANGE_HPP
 
+#include <cstdint>
 #include <queue>
 #include <vector>