Add character creation screen with race/class/appearance customization

Implements a full character creation UI integrated into the existing flow.
In single-player mode, auth screen now goes to character creation before
entering the world. In online mode, a "Create Character" button on the
character selection screen sends CMSG_CHAR_CREATE to the server. Includes
WoW 3.3.5a race/class combo validation and appearance range limits.

include/game/character.hpp

@@ -110,6 +110,14 @@ struct Character {
     bool hasPet() const { return pet.exists(); }
 };
 
+// Race/class combo and appearance range validation (WoW 3.3.5a)
+bool isValidRaceClassCombo(Race race, Class cls);
+uint8_t getMaxSkin(Race race, Gender gender);
+uint8_t getMaxFace(Race race, Gender gender);
+uint8_t getMaxHairStyle(Race race, Gender gender);
+uint8_t getMaxHairColor(Race race, Gender gender);
+uint8_t getMaxFacialFeature(Race race, Gender gender);
+
 /**
  * Get human-readable race name
  */

include/game/game_handler.hpp

@@ -102,6 +102,11 @@ public:
      */
     const std::vector<Character>& getCharacters() const { return characters; }
 
+    void createCharacter(const CharCreateData& data);
+
+    using CharCreateCallback = std::function<void(bool success, const std::string& message)>;
+    void setCharCreateCallback(CharCreateCallback cb) { charCreateCallback_ = std::move(cb); }
+
     /**
      * Select and log in with a character
      * @param characterGuid GUID of character to log in with
@@ -210,6 +215,7 @@ public:
     // Single-player mode
     void setSinglePlayerMode(bool sp) { singlePlayerMode_ = sp; }
     bool isSinglePlayerMode() const { return singlePlayerMode_; }
+    void simulateMotd(const std::vector<std::string>& lines);
 
     // NPC death callback (single-player)
     using NpcDeathCallback = std::function<void(uint64_t guid)>;
@@ -375,6 +381,9 @@ private:
     void handleGroupUninvite(network::Packet& packet);
     void handlePartyCommandResult(network::Packet& packet);
 
+    // ---- Character creation handler ----
+    void handleCharCreateResponse(network::Packet& packet);
+
     // ---- XP handler ----
     void handleXpGain(network::Packet& packet);
 
@@ -515,6 +524,7 @@ private:
     // Callbacks
     WorldConnectSuccessCallback onSuccess;
     WorldConnectFailureCallback onFailure;
+    CharCreateCallback charCreateCallback_;
 
     // ---- XP tracking ----
     uint32_t playerXp_ = 0;

include/game/opcodes.hpp

@@ -12,6 +12,7 @@ enum class Opcode : uint16_t {
     // ---- Client to Server (Core) ----
     CMSG_PING                       = 0x1DC,
     CMSG_AUTH_SESSION                = 0x1ED,
+    CMSG_CHAR_CREATE                 = 0x036,
     CMSG_CHAR_ENUM                   = 0x037,
     CMSG_PLAYER_LOGIN                = 0x03D,
 
@@ -35,6 +36,7 @@ enum class Opcode : uint16_t {
     // ---- Server to Client (Core) ----
     SMSG_AUTH_CHALLENGE              = 0x1EC,
     SMSG_AUTH_RESPONSE               = 0x1EE,
+    SMSG_CHAR_CREATE                 = 0x03A,
     SMSG_CHAR_ENUM                   = 0x03B,
     SMSG_PONG                        = 0x1DD,
     SMSG_LOGIN_VERIFY_WORLD          = 0x236,

include/game/world_packets.hpp

@@ -2,6 +2,7 @@
 
 #include "network/packet.hpp"
 #include "game/opcodes.hpp"
+#include "game/character.hpp"
 #include "game/entity.hpp"
 #include "game/spell_defines.hpp"
 #include "game/group_defines.hpp"
@@ -167,6 +168,47 @@ public:
     static bool parse(network::Packet& packet, CharEnumResponse& response);
 };
 
+// ============================================================
+// Character Creation
+// ============================================================
+
+enum class CharCreateResult : uint8_t {
+    SUCCESS              = 0x00,
+    ERROR                = 0x01,
+    FAILED               = 0x02,
+    NAME_IN_USE          = 0x03,
+    DISABLED             = 0x04,
+    PVP_TEAMS_VIOLATION  = 0x05,
+    SERVER_LIMIT         = 0x06,
+    ACCOUNT_LIMIT        = 0x07,
+};
+
+struct CharCreateData {
+    std::string name;
+    Race race;
+    Class characterClass;
+    Gender gender;
+    uint8_t skin = 0;
+    uint8_t face = 0;
+    uint8_t hairStyle = 0;
+    uint8_t hairColor = 0;
+    uint8_t facialHair = 0;
+};
+
+class CharCreatePacket {
+public:
+    static network::Packet build(const CharCreateData& data);
+};
+
+struct CharCreateResponseData {
+    CharCreateResult result;
+};
+
+class CharCreateResponseParser {
+public:
+    static bool parse(network::Packet& packet, CharCreateResponseData& data);
+};
+
 /**
  * CMSG_PLAYER_LOGIN packet builder
  *