base_n: fixvecToString's O(n²) blowup on large inputs (used bybase64.encodeandcbase32) — a balanced recursive split replaces the per-chunkpopFront, giving true O(n log n) #1202
base_n: fix vecToString's O(n²) blowup on large inputs (used by base64.encode and cbase32) — a balanced recursive split replaces the per-chunk popFront, giving true O(n log n) #1202