pub fn dedup_compact_edges(edges: &mut Vec<CompactEdge>)Expand description
Merge duplicate (src, dst) entries: weight = max across duplicates,
category = first occurrence in input order (builder order), matching
the historical EdgeDict max-merge + or_insert category semantics.
Requires a stable sort so first-in-input stays first-in-group —
par_sort_by is a stable parallel merge sort, so its output is
bit-identical to sort_by while cutting the dominant serial phase of a
tens-of-millions-edge build (#196).