Fix capturing king

app.py

@@ -353,6 +353,11 @@ def get_piece_moves(piece_kind, board: Board, is_white, src: str) -> list[Coord]
                 p.value.isupper() != is_white or p.value == "E"
             ):
                 valids.append(target.copy())
+    v_temp = [a for a in valids]
+    valids.clear()
+    for a in v_temp:
+        if board.index_coord(a).value.lower != "k":
+            valids.append(a)
     return valids