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- scoring.rs (152 lines) — scoring fns superseded by KlondikeAdapter; move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/src/klondike_adapter.rs

@@ -237,8 +237,7 @@ pub fn card_to_kl(card: &crate::card::Card) -> KlCard {
 /// Convert a [`card_game::Card`] back to our [`crate::card::Card`], assigning
 /// a stable `id` derived from the suit and rank (0–51, Clubs-first ordering).
 ///
-/// This id matches the id assigned in [`crate::deck::Deck::new`] and is
-/// consistent for the same logical card across all reconstructions.
+/// The id is consistent for the same logical card across all reconstructions.
 pub fn card_from_kl(card: &KlCard) -> crate::card::Card {
     let suit = suit_from_kl(card.suit());
     let rank = rank_from_kl(card.rank());
@@ -518,3 +517,12 @@ impl TryFrom<SavedInstruction> for KlondikeInstruction {
         })
     }
 }
+
+/// Time bonus added to the score on a win: `700_000 / elapsed_seconds`.
+/// Returns 0 when `elapsed_seconds` is 0 to avoid division by zero.
+pub fn compute_time_bonus(elapsed_seconds: u64) -> i32 {
+    if elapsed_seconds == 0 {
+        return 0;
+    }
+    (700_000u64 / elapsed_seconds).min(i32::MAX as u64) as i32
+}