安全模块大规模重构：151文件从com.aluer.security分包到8个子包

新包结构：
- com.aluer.anticheat.combat (16) — KillAura/Reach/Criticals/CrystalAura/Totem等战斗反作弊
- com.aluer.anticheat.movement (18) — Fly/Speed/Jesus/NoFall/Timer/Phase等移动反作弊
- com.aluer.anticheat.world (14) — Nuker/Xray/AutoMine/VeinMiner等世界反作弊
- com.aluer.anticheat.player (8) — FakePlayer/AltAccount/NameSpoof等玩家反作弊
- com.aluer.network (32) — DDoS/Protocol/TokenBucket/Firewall等网络安全
- com.aluer.server (10) — ChunkLoad/EntityCount/Redstone/CrashExploit等服务器保护
- com.aluer.chat (5) — ChatFlood/Advertisement/Phishing/CommandAbuse等聊天安全
- com.aluer.defense (50) — WAF/IDS/IPS/Honeypot/EDR/Forensics等纵深防御

所有package声明+跨包import已更新，323测试全绿

src/main/java/com/aluer/console/RemoteSshGatewayService.java

@@ -2,7 +2,7 @@ package com.aluer.console;
 
 import com.aluer.audit.SecurityAuditService;
 import com.aluer.config.ServerGuardConfig;
-import com.aluer.security.CommandExecutionGuardService;
+import com.aluer.defense.CommandExecutionGuardService;
 import com.jcraft.jsch.ChannelExec;
 import com.jcraft.jsch.HostKey;
 import com.jcraft.jsch.JSch;