Add Tier 6 commands: party/raid management

- Uninvite/kick: /uninvite, /kick <player name> to remove player from party/raid
- Leave party: /leave, /leaveparty to leave current group
- Main tank: /maintank, /mt to set target as main tank (uses raid marker index 0)
- Main assist: /mainassist, /ma to set target as main assist (uses raid marker index 1)
- Clear markers: /clearmaintank, /clearmainassist to remove designations
- Raid info: /raidinfo to display raid lockouts and saved instances

Added opcodes:
- CMSG_REQUEST_RAID_INFO (0x2CD) for requesting raid lockout info
- SMSG_RAID_INSTANCE_INFO (0x2CC) for receiving raid info response

New packet builders:
- GroupUninvitePacket for removing players from group
- GroupDisbandPacket for leaving party (with logging)
- RaidTargetUpdatePacket for setting raid markers (main tank/assist)
- RequestRaidInfoPacket for querying raid lockouts

All commands include proper validation and user feedback.

include/game/world_packets.hpp

@@ -884,6 +884,39 @@ public:
     static network::Packet build();
 };
 
+// ============================================================
+// Party/Raid Management
+// ============================================================
+
+/** CMSG_GROUP_UNINVITE_GUID packet builder */
+class GroupUninvitePacket {
+public:
+    static network::Packet build(const std::string& playerName);
+};
+
+/** CMSG_GROUP_DISBAND packet builder */
+class GroupDisbandPacket {
+public:
+    static network::Packet build();
+};
+
+/** MSG_RAID_TARGET_UPDATE packet builder */
+class RaidTargetUpdatePacket {
+public:
+    /**
+     * Build raid target marker update packet
+     * @param targetIndex 0-7 for raid icons, 0 = MainTank, 1 = MainAssist
+     * @param targetGuid GUID to mark, or 0 to clear
+     */
+    static network::Packet build(uint8_t targetIndex, uint64_t targetGuid);
+};
+
+/** CMSG_REQUEST_RAID_INFO packet builder */
+class RequestRaidInfoPacket {
+public:
+    static network::Packet build();
+};
+
 // ============================================================
 // Random Roll
 // ============================================================
@@ -1315,12 +1348,6 @@ public:
     static network::Packet build();
 };
 
-/** CMSG_GROUP_DISBAND (leave party) packet builder */
-class GroupDisbandPacket {
-public:
-    static network::Packet build();
-};
-
 /** SMSG_GROUP_LIST parser */
 class GroupListParser {
 public: