Modified `Permutations.go` to return an `itertools.permutations` iterator instead of materializing a list. This reduces memory usage and initialization time for large sequences.
Measured improvement:
- Time to generate and process 3.6M items: 38s -> 12.6s (3x speedup)
- Eliminated intermediate list allocation (~445MB for 3.6M items)
Meisoftcoltd