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- scoring.rs (152 lines) — scoring fns superseded by KlondikeAdapter; move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>

solitaire_core/Cargo.toml

@@ -7,6 +7,5 @@ edition.workspace = true
 [dependencies]
 serde     = { workspace = true }
 thiserror = { workspace = true }
-rand      = { workspace = true }
 klondike  = { workspace = true }
 card_game = { workspace = true }