refactor(ff-game): 调整金额参数最小值限制

- 将 GameExchangeBalanceRequest 类中的 amount 字段的最小值限制从 0.1 修改为 0.01
- 此修改通过调整 @DecimalMin 注解的 value 属性来实现

ff-game/src/main/java/com/ff/api/request/GameExchangeBalanceRequest.java

@@ -43,7 +43,7 @@ public class GameExchangeBalanceRequest implements Serializable {
      * 金额
      */
     @NotNull(message = "amount不能为空")
-    @DecimalMin(value = "0.1", message = "amount必须大于等于0.1")
+    @DecimalMin(value = "0.01", message = "amount必须大于等于0.1")
     @Max(value = 999999999, message = "amount最大值为999999999")
     private BigDecimal amount;