refactor(core): move compute_time_bonus into scoring module

The win-time bonus is Ferrous house-rule scoring policy, not a bridge to
the upstream klondike crate, so it does not belong in klondike_adapter.
Relocate it to a dedicated solitaire_core::scoring module and update the
sole caller (win_summary_plugin) and the adapter/settings doc references.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

solitaire_core/src/klondike_adapter.rs

@@ -3,7 +3,9 @@
 //! [`KlondikeAdapter`] is a pure helper namespace for:
 //! - building [`KlondikeConfig`] from Ferrous settings
 //! - translating between local and upstream types
-//! - applying Ferrous-specific scoring policy on top of upstream defaults
+//!
+//! Ferrous-specific scoring policy (the win-time bonus) lives in
+//! [`crate::scoring`], not here.
 //!
 //! All `From` / `TryFrom` conversions between `solitaire_core` product types and
 //! upstream `card_game` / `klondike` types live here so that the product modules
@@ -14,11 +16,11 @@ use klondike::{
     SkipCards, Tableau,
 };
 
-/// Bridges `solitaire_core` game config and scoring to the upstream `klondike` crate.
+/// Bridges `solitaire_core` game config to the upstream `klondike` crate.
 ///
 /// This type is intentionally zero-sized: it does not carry mutable runtime
-/// state, and exists only as a namespace for configuration, conversion, and
-/// scoring helpers.
+/// state, and exists only as a namespace for configuration and conversion
+/// helpers.
 #[derive(Debug, Clone, Copy, Default, PartialEq, Eq)]
 pub struct KlondikeAdapter;
 
@@ -81,12 +83,3 @@ pub fn skip_cards_from_count(skip: usize) -> Option<SkipCards> {
         _ => None,
     }
 }
-
-/// 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
-}