fix: clippy warnings — too_many_arguments + Default impls + needless_borrows

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

core/src/ai/killer.rs

@@ -7,12 +7,18 @@ pub struct KillerTable {
     moves: [[Option<Position>; SLOTS_PER_DEPTH]; MAX_DEPTH],
 }
 
-impl KillerTable {
-    pub fn new() -> Self {
+impl Default for KillerTable {
+    fn default() -> Self {
         Self {
             moves: [[None; SLOTS_PER_DEPTH]; MAX_DEPTH],
         }
     }
+}
+
+impl KillerTable {
+    pub fn new() -> Self {
+        Self::default()
+    }
 
     /// 记录产生剪枝的走法，同一位置不会重复存储
     pub fn record(&mut self, depth: usize, pos: Position) {

core/src/ai/opening.rs

@@ -6,14 +6,20 @@ pub struct OpeningBook {
     positions: HashMap<ZobristHash, Vec<Position>>,
 }
 
-impl OpeningBook {
-    pub fn new() -> Self {
+impl Default for OpeningBook {
+    fn default() -> Self {
         let mut book = Self {
             positions: HashMap::new(),
         };
         book.load();
         book
     }
+}
+
+impl OpeningBook {
+    pub fn new() -> Self {
+        Self::default()
+    }
 
     fn load(&mut self) {
         let openings: Vec<Vec<(usize, usize)>> = vec![

core/src/ai/search.rs

@@ -79,6 +79,7 @@ impl AiEngine for AlphaBetaAi {
 }
 
 impl AlphaBetaAi {
+    #[allow(clippy::too_many_arguments)]
     fn search_depth(
         &self,
         board: &Board,
@@ -162,6 +163,7 @@ impl AlphaBetaAi {
         (best_pos, completed)
     }
 
+    #[allow(clippy::too_many_arguments)]
     fn negamax(
         &self,
         board: &Board,