Feat improve list ruin

[NewBornRustacean]

closes #45

Summary

Fixes ListRuinMoveSelector so empty routes no longer consume moves_per_step sampling attempts. Previously, the selector sampled from all entities and dropped attempts that selected an empty route. This could make the selector yield fewer ruin moves than configured when the solution contained empty routes.

Changes

• Sample ruin moves from (entity_index, list_length) pairs where list_length > 0.
• Add regression coverage verifying that empty routes do not reduce the number of yielded moves when at least one non-empty route exists.

[NewBornRustacean]

note:
existing failure - some macro related tests fails. 😿

[blackopsrepl]

note: existing failure - some macro related tests fails. 😿

No issue - that was just the CI hanging for some reason. I reran it and it's green. Thank you!