fix: inspect (packed GUID), follow (client-side auto-walk); add loot/raid commands

Inspect: CMSG_INSPECT was writing full uint64 GUID instead of packed GUID.
Server silently rejected the malformed packet. Fixed both InspectPacket and
QueryInspectAchievementsPacket to use writePackedGuid().

Follow: was a no-op (only stored GUID). Added client-side auto-follow system:
camera controller walks toward followed entity, faces target, cancels on
WASD/mouse input, stops within 3 units, cancels at 40+ units distance.

Party commands:
- /lootmethod (ffa/roundrobin/master/group/nbg) sends CMSG_LOOT_METHOD
- /lootthreshold (0-5 or quality name) sets minimum loot quality
- /raidconvert converts party to raid (leader only)

Equipment diagnostic logging still active for debugging naked players.

include/game/world_packets.hpp

@@ -1315,6 +1315,23 @@ public:
     static network::Packet build();
 };
 
+/** CMSG_GROUP_RAID_CONVERT packet builder */
+class GroupRaidConvertPacket {
+public:
+    static network::Packet build();
+};
+
+/** CMSG_LOOT_METHOD packet builder */
+class SetLootMethodPacket {
+public:
+    /**
+     * @param method 0=FFA, 1=RoundRobin, 2=MasterLoot, 3=GroupLoot, 4=NeedBeforeGreed
+     * @param threshold item quality threshold (0-6)
+     * @param masterLooterGuid GUID of master looter (only relevant for method=2)
+     */
+    static network::Packet build(uint32_t method, uint32_t threshold, uint64_t masterLooterGuid);
+};
+
 /** MSG_RAID_TARGET_UPDATE packet builder */
 class RaidTargetUpdatePacket {
 public: