Implement group loot roll: SMSG_LOOT_ROLL, SMSG_LOOT_ROLL_WON, CMSG_LOOT_ROLL

- Parse SMSG_LOOT_ROLL: if rollType==128 and it's our player, store
  pending roll (itemId, slot, name from itemInfoCache_) and show popup;
  otherwise show chat notification of another player's roll result
- Parse SMSG_LOOT_ROLL_WON: show winner announcement in chat with item
  name and roll type/value
- sendLootRoll() sends CMSG_LOOT_ROLL (objectGuid+slot+rollType) and
  clears pending roll state
- SMSG_LOOT_MASTER_LIST consumed silently (no UI yet)
- renderLootRollPopup(): ImGui window with Need/Greed/Disenchant/Pass
  buttons; item name colored by quality (poor/common/uncommon/rare/epic/
  legendary color scale)

include/game/game_handler.hpp

@@ -758,6 +758,19 @@ public:
     void setAutoLoot(bool enabled) { autoLoot_ = enabled; }
     bool isAutoLoot() const { return autoLoot_; }
 
+    // Group loot roll
+    struct LootRollEntry {
+        uint64_t objectGuid    = 0;
+        uint32_t slot          = 0;
+        uint32_t itemId        = 0;
+        std::string itemName;
+        uint8_t  itemQuality   = 0;
+    };
+    bool hasPendingLootRoll() const { return pendingLootRollActive_; }
+    const LootRollEntry& getPendingLootRoll() const { return pendingLootRoll_; }
+    void sendLootRoll(uint64_t objectGuid, uint32_t slot, uint8_t rollType);
+    // rollType: 0=need, 1=greed, 2=disenchant, 96=pass
+
     // NPC Gossip
     void interactWithNpc(uint64_t guid);
     void interactWithGameObject(uint64_t guid);
@@ -1258,6 +1271,8 @@ private:
     void handleDuelRequested(network::Packet& packet);
     void handleDuelComplete(network::Packet& packet);
     void handleDuelWinner(network::Packet& packet);
+    void handleLootRoll(network::Packet& packet);
+    void handleLootRollWon(network::Packet& packet);
 
     // ---- LFG / Dungeon Finder handlers ----
     void handleLfgJoinResult(network::Packet& packet);
@@ -1637,6 +1652,10 @@ private:
     bool lootWindowOpen = false;
     bool autoLoot_ = false;
     LootResponseData currentLoot;
+
+    // Group loot roll state
+    bool          pendingLootRollActive_ = false;
+    LootRollEntry pendingLootRoll_;
     struct LocalLootState {
         LootResponseData data;
         bool moneyTaken = false;

include/ui/game_screen.hpp

@@ -205,6 +205,7 @@ private:
     void renderPartyFrames(game::GameHandler& gameHandler);
     void renderGroupInvitePopup(game::GameHandler& gameHandler);
     void renderDuelRequestPopup(game::GameHandler& gameHandler);
+    void renderLootRollPopup(game::GameHandler& gameHandler);
     void renderBuffBar(game::GameHandler& gameHandler);
     void renderLootWindow(game::GameHandler& gameHandler);
     void renderGossipWindow(game::GameHandler& gameHandler);