Add quest details dialog, fix vendor UI, suppress both-button clicks

Parse SMSG_QUESTGIVER_QUEST_DETAILS and show quest text with Accept/
Decline buttons. Vendor window now shows item names with quality colors,
stat tooltips on hover, player money, and closes properly via X button.
Suppress left/right-click targeting and interaction when the other mouse
button is held (both-button run forward).

include/game/game_handler.hpp

@@ -322,16 +322,25 @@ public:
     void interactWithNpc(uint64_t guid);
     void selectGossipOption(uint32_t optionId);
     void selectGossipQuest(uint32_t questId);
+    void acceptQuest();
+    void declineQuest();
     void closeGossip();
     bool isGossipWindowOpen() const { return gossipWindowOpen; }
     const GossipMessageData& getCurrentGossip() const { return currentGossip; }
+    bool isQuestDetailsOpen() const { return questDetailsOpen; }
+    const QuestDetailsData& getQuestDetails() const { return currentQuestDetails; }
 
     // Vendor
     void openVendor(uint64_t npcGuid);
+    void closeVendor();
     void buyItem(uint64_t vendorGuid, uint32_t itemId, uint32_t slot, uint8_t count);
     void sellItem(uint64_t vendorGuid, uint64_t itemGuid, uint8_t count);
     bool isVendorWindowOpen() const { return vendorWindowOpen; }
     const ListInventoryData& getVendorItems() const { return currentVendorItems; }
+    const ItemQueryResponseData* getItemInfo(uint32_t itemId) const {
+        auto it = itemInfoCache_.find(itemId);
+        return (it != itemInfoCache_.end()) ? &it->second : nullptr;
+    }
 
     /**
      * Set callbacks
@@ -461,6 +470,7 @@ private:
     void handleLootRemoved(network::Packet& packet);
     void handleGossipMessage(network::Packet& packet);
     void handleGossipComplete(network::Packet& packet);
+    void handleQuestDetails(network::Packet& packet);
     void handleListInventory(network::Packet& packet);
     LootResponseData generateLocalLoot(uint64_t guid);
     void simulateLootResponse(const LootResponseData& data);
@@ -602,6 +612,10 @@ private:
     bool gossipWindowOpen = false;
     GossipMessageData currentGossip;
 
+    // Quest details
+    bool questDetailsOpen = false;
+    QuestDetailsData currentQuestDetails;
+
     // Vendor
     bool vendorWindowOpen = false;
     ListInventoryData currentVendorItems;

include/game/world_packets.hpp

@@ -1182,6 +1182,24 @@ public:
     static network::Packet build(uint64_t npcGuid, uint32_t questId);
 };
 
+/** SMSG_QUESTGIVER_QUEST_DETAILS data (simplified) */
+struct QuestDetailsData {
+    uint64_t npcGuid = 0;
+    uint32_t questId = 0;
+    std::string title;
+    std::string details;      // Quest description text
+    std::string objectives;   // Objectives text
+    uint32_t suggestedPlayers = 0;
+    uint32_t rewardMoney = 0;
+    uint32_t rewardXp = 0;
+};
+
+/** SMSG_QUESTGIVER_QUEST_DETAILS parser */
+class QuestDetailsParser {
+public:
+    static bool parse(network::Packet& packet, QuestDetailsData& data);
+};
+
 // ============================================================
 // Phase 5: Vendor
 // ============================================================

include/ui/game_screen.hpp

@@ -131,6 +131,7 @@ private:
     void renderBuffBar(game::GameHandler& gameHandler);
     void renderLootWindow(game::GameHandler& gameHandler);
     void renderGossipWindow(game::GameHandler& gameHandler);
+    void renderQuestDetailsWindow(game::GameHandler& gameHandler);
     void renderVendorWindow(game::GameHandler& gameHandler);
     void renderTeleporterPanel();
     void renderEscapeMenu();