Implement SMSG_RESUME_CAST_BAR, SMSG_THREAT_UPDATE, SMSG_UPDATE_INSTANCE_ENCOUNTER_UNIT

- SMSG_RESUME_CAST_BAR: parse packed_guid caster/target + spellId + remainingMs +
  totalMs; restores cast bar state when server re-syncs a cast in progress
- SMSG_THREAT_UPDATE: properly consume packed_guid host/target + threat entries
  to suppress unhandled packet warnings
- SMSG_UPDATE_INSTANCE_ENCOUNTER_UNIT: track up to 5 boss encounter unit guids
  per slot; expose via getEncounterUnitGuid(slot); clear on world transfer
  These guids identify active boss units for raid/boss frame display.

include/game/game_handler.hpp

@@ -772,6 +772,10 @@ public:
         bool     extended    = false;
     };
     const std::vector<InstanceLockout>& getInstanceLockouts() const { return instanceLockouts_; }
+    // Returns boss unit guid for the given encounter slot (0 if none)
+    uint64_t getEncounterUnitGuid(uint32_t slot) const {
+        return (slot < kMaxEncounterSlots) ? encounterUnitGuids_[slot] : 0;
+    }
 
     // ---- LFG / Dungeon Finder ----
     enum class LfgState : uint8_t {
@@ -1738,6 +1742,10 @@ private:
     // Instance / raid lockouts
     std::vector<InstanceLockout> instanceLockouts_;
 
+    // Instance encounter boss units (slots 0-4 from SMSG_UPDATE_INSTANCE_ENCOUNTER_UNIT)
+    static constexpr uint32_t kMaxEncounterSlots = 5;
+    std::array<uint64_t, kMaxEncounterSlots> encounterUnitGuids_ = {};  // 0 = empty slot
+
     // LFG / Dungeon Finder state
     LfgState lfgState_        = LfgState::None;
     uint32_t lfgDungeonId_    = 0;   // current dungeon entry

src/game/game_handler.cpp

@@ -4547,11 +4547,61 @@ void GameHandler::handlePacket(network::Packet& packet) {
         case Opcode::SMSG_ITEM_REFUND_INFO_RESPONSE:
         case Opcode::SMSG_ITEM_ENCHANT_TIME_UPDATE:
         case Opcode::SMSG_LOOT_LIST:
-        case Opcode::SMSG_RESUME_CAST_BAR:
+        case Opcode::SMSG_RESUME_CAST_BAR: {
-        case Opcode::SMSG_THREAT_UPDATE:
+            // packed_guid caster + packed_guid target + uint32 spellId
+            // + uint32 remainingMs + uint32 totalMs + uint8 schoolMask
+            auto remaining = [&]() { return packet.getSize() - packet.getReadPos(); };
+            if (remaining() < 1) break;
+            uint64_t caster = UpdateObjectParser::readPackedGuid(packet);
+            if (remaining() < 1) break;
+            (void)UpdateObjectParser::readPackedGuid(packet); // target
+            if (remaining() < 12) break;
+            uint32_t spellId   = packet.readUInt32();
+            uint32_t remainMs  = packet.readUInt32();
+            uint32_t totalMs   = packet.readUInt32();
+            if (caster == playerGuid && totalMs > 0) {
+                casting              = true;
+                currentCastSpellId   = spellId;
+                castTimeTotal        = totalMs   / 1000.0f;
+                castTimeRemaining    = remainMs  / 1000.0f;
+                LOG_DEBUG("SMSG_RESUME_CAST_BAR: spell=", spellId,
+                          " remaining=", remainMs, "ms total=", totalMs, "ms");
+            }
+            break;
+        }
+        case Opcode::SMSG_THREAT_UPDATE: {
+            // packed_guid (unit) + packed_guid (target) + uint32 count
+            // + count × (packed_guid victim + uint32 threat) — consume to suppress warnings
+            if (packet.getSize() - packet.getReadPos() < 1) break;
+            (void)UpdateObjectParser::readPackedGuid(packet);
+            if (packet.getSize() - packet.getReadPos() < 1) break;
+            (void)UpdateObjectParser::readPackedGuid(packet);
+            if (packet.getSize() - packet.getReadPos() < 4) break;
+            uint32_t cnt = packet.readUInt32();
+            for (uint32_t i = 0; i < cnt && packet.getSize() - packet.getReadPos() >= 1; ++i) {
+                (void)UpdateObjectParser::readPackedGuid(packet);
+                if (packet.getSize() - packet.getReadPos() >= 4)
+                    packet.readUInt32();
+            }
+            break;
+        }
+        case Opcode::SMSG_UPDATE_INSTANCE_ENCOUNTER_UNIT: {
+            // uint32 slot + packed_guid unit (0 packed = clear slot)
+            if (packet.getSize() - packet.getReadPos() < 5) {
+                packet.setReadPos(packet.getSize());
+                break;
+            }
+            uint32_t slot = packet.readUInt32();
+            uint64_t unit = UpdateObjectParser::readPackedGuid(packet);
+            if (slot < kMaxEncounterSlots) {
+                encounterUnitGuids_[slot] = unit;
+                LOG_DEBUG("SMSG_UPDATE_INSTANCE_ENCOUNTER_UNIT: slot=", slot,
+                          " guid=0x", std::hex, unit, std::dec);
+            }
+            break;
+        }
         case Opcode::SMSG_UPDATE_INSTANCE_OWNERSHIP:
         case Opcode::SMSG_UPDATE_LAST_INSTANCE:
-        case Opcode::SMSG_UPDATE_INSTANCE_ENCOUNTER_UNIT:
         case Opcode::SMSG_SEND_ALL_COMBAT_LOG:
         case Opcode::SMSG_SET_PROJECTILE_POSITION:
         case Opcode::SMSG_AUCTION_LIST_PENDING_SALES:
@@ -5443,6 +5493,9 @@ void GameHandler::handleLoginVerifyWorld(network::Packet& packet) {
         mountCallback_(0);
     }
 
+    // Clear boss encounter unit slots on world transfer
+    encounterUnitGuids_.fill(0);
+
     // Suppress area triggers on initial login — prevents exit portals from
     // immediately firing when spawning inside a dungeon/instance.
     activeAreaTriggers_.clear();