chore(core): delete deck.rs and scoring.rs

- deck.rs (193 lines) — Deck/deal_klondike replaced by Klondike::with_seed()
- scoring.rs (152 lines) — scoring fns superseded by KlondikeAdapter; move
  compute_time_bonus to klondike_adapter.rs, update win_summary_plugin import
- Remove rand dep from solitaire_core (only used by deck.rs)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Cargo.lock

@@ -7034,7 +7034,6 @@ version = "0.1.0"
 dependencies = [
  "card_game",
  "klondike",
- "rand 0.9.4",
  "serde",
  "thiserror 2.0.18",
 ]