feat: 榜单同步服务端（读stats+网络包下发）

BoardSyncPayload自定义包，BoardSyncManager读原版stats（挖掘总数/死亡数）构建Top10排行。顺带补回之前漏掉的BotListManager.load()。

src/main/java/com/github/zly2006/carpetslsaddition/util/BoardManager.java

@@ -0,0 +1,71 @@
+package com.github.zly2006.carpetslsaddition.util;
+
+import com.github.zly2006.carpetslsaddition.ServerMain;
+import net.minecraft.network.chat.Component;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.scores.Objective;
+import net.minecraft.world.scores.ScoreAccess;
+import net.minecraft.world.scores.ScoreHolder;
+import net.minecraft.world.scores.Scoreboard;
+import net.minecraft.world.scores.criteria.ObjectiveCriteria;
+
+/**
+ * 死亡榜 / 挖掘榜的 scoreboard 管理器（服务端）。
+ *
+ * <ul>
+ *   <li>{@code sls_deaths}：使用原版 {@link ObjectiveCriteria#DEATH_COUNT} 判据，自动统计死亡次数。</li>
+ *   <li>{@code sls_mined}：使用 {@link ObjectiveCriteria#DUMMY} 判据，由 {@code BoardEvents} 在破坏方块时写入。</li>
+ * </ul>
+ *
+ * <p>objective 在服务器启动时自动创建；客户端会同步到这两个 objective，用于 HUD 显示。
+ */
+public final class BoardManager {
+
+    private BoardManager() {}
+
+    public static final String OBJ_DEATHS = "sls_deaths";
+    public static final String OBJ_MINED = "sls_mined";
+
+    /** 确保两个 objective 存在（服务器启动/重载时调用）。 */
+    public static void ensureObjectives(MinecraftServer server) {
+        Scoreboard sb = server.getScoreboard();
+        if (sb.getObjective(OBJ_DEATHS) == null) {
+            sb.addObjective(
+                    OBJ_DEATHS,
+                    ObjectiveCriteria.DEATH_COUNT,
+                    Component.literal("死亡榜"),
+                    ObjectiveCriteria.RenderType.INTEGER,
+                    true,
+                    null
+            );
+            ServerMain.LOGGER.info("[SLSA] created scoreboard objective {}", OBJ_DEATHS);
+        }
+        if (sb.getObjective(OBJ_MINED) == null) {
+            sb.addObjective(
+                    OBJ_MINED,
+                    ObjectiveCriteria.DUMMY,
+                    Component.literal("挖掘榜"),
+                    ObjectiveCriteria.RenderType.INTEGER,
+                    true,
+                    null
+            );
+            ServerMain.LOGGER.info("[SLSA] created scoreboard objective {}", OBJ_MINED);
+        }
+    }
+
+    /** 玩家破坏一个方块 → 挖掘榜 +1。 */
+    public static void onBlockMined(ServerPlayer player, int count) {
+        MinecraftServer server = ServerMain.server;
+        if (server == null) {
+            return;
+        }
+        Scoreboard sb = server.getScoreboard();
+        Objective obj = sb.getObjective(OBJ_MINED);
+        if (obj == null) {
+            return;
+        }
+        ScoreAccess access = sb.getOrCreatePlayerScore((ScoreHolder) player, obj);
+        access.add(count);
+    }
+}