refactor: common and auth packets as structs

Adds CommonPackets (ServiceType::COMMON): ClientVersionConfirm (the
client's handshake, with the handler that logs it and answers),
ServerVersionConfirm, DisconnectNotify and GeneralNotify (layout from the
1.10.64 client's PacketHandler_MSG_SERVER_GENERAL_NOTIFY; DLU does not send
it yet). AuthPackets::LoginRequest reads the login and keeps the old login
logic in its Handle; ClientPackets::LoginResponse (with the Stamp list)
replaces the hand written response, and AuthPackets::SendLoginResponse
fills it from the settings as before. dServer::Disconnect writes a
DisconnectNotify. AuthServer's if-chain and WorldServer's COMMON case
become CommonPackets::Handle / AuthPackets::Handle, dispatch maps that
read the struct, drop and log it if it does not deserialize, then Handle.
HandleHandshake and SendHandshake are gone.

No wire change. Verified against a frozen verbatim copy of the old
functions (tests/dGameTests/dNetTests/Legacy): the old handshake and login
handlers and the new dispatchers are fed the same packets and must send
identical bytes to the same address (same RNG seed for the session key),
over grids of versions, service types, ports, response codes, error
messages, IPs and stamp lists; plus hand computed golden bytes, round
trips, truncation checks, and a deliberate field width mutation that made
the tests fail. The only behaviour difference: truncated handshake and
login packets are now dropped instead of handled with whatever was read.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

dNet/ClientPackets.h

@@ -7,12 +7,85 @@
 #define CLIENTPACKETS_H
 
 #include <cstdint>
+#include <ctime>
 #include <string>
+#include <vector>
+
+#include "BitStreamUtils.h"
+#include "MessageType/Client.h"
+
+enum class eLoginResponse : uint8_t;
 
 class PositionUpdate;
 
 struct Packet;
 
+enum class eStamps : uint32_t {
+	PASSPORT_AUTH_START,
+	PASSPORT_AUTH_BYPASS,
+	PASSPORT_AUTH_ERROR,
+	PASSPORT_AUTH_DB_SELECT_START,
+	PASSPORT_AUTH_DB_SELECT_FINISH,
+	PASSPORT_AUTH_DB_INSERT_START,
+	PASSPORT_AUTH_DB_INSERT_FINISH,
+	PASSPORT_AUTH_LEGOINT_COMMUNICATION_START,
+	PASSPORT_AUTH_LEGOINT_RECEIVED,
+	PASSPORT_AUTH_LEGOINT_THREAD_SPAWN,
+	PASSPORT_AUTH_LEGOINT_WEBSERVICE_START,
+	PASSPORT_AUTH_LEGOINT_WEBSERVICE_FINISH,
+	PASSPORT_AUTH_LEGOINT_LEGOCLUB_START,
+	PASSPORT_AUTH_LEGOINT_LEGOCLUB_FINISH,
+	PASSPORT_AUTH_LEGOINT_THREAD_FINISH,
+	PASSPORT_AUTH_LEGOINT_REPLY,
+	PASSPORT_AUTH_LEGOINT_ERROR,
+	PASSPORT_AUTH_LEGOINT_COMMUNICATION_END,
+	PASSPORT_AUTH_LEGOINT_DISCONNECT,
+	PASSPORT_AUTH_WORLD_COMMUNICATION_START,
+	PASSPORT_AUTH_CLIENT_OS,
+	PASSPORT_AUTH_WORLD_PACKET_RECEIVED,
+	PASSPORT_AUTH_IM_COMMUNICATION_START,
+	PASSPORT_AUTH_IM_LOGIN_START,
+	PASSPORT_AUTH_IM_LOGIN_ALREADY_LOGGED_IN,
+	PASSPORT_AUTH_IM_OTHER_LOGIN_REMOVED,
+	PASSPORT_AUTH_IM_LOGIN_QUEUED,
+	PASSPORT_AUTH_IM_LOGIN_RESPONSE,
+	PASSPORT_AUTH_IM_COMMUNICATION_END,
+	PASSPORT_AUTH_WORLD_SESSION_CONFIRM_TO_AUTH,
+	PASSPORT_AUTH_WORLD_COMMUNICATION_FINISH,
+	PASSPORT_AUTH_WORLD_DISCONNECT,
+	NO_LEGO_INTERFACE,
+	DB_ERROR,
+	GM_REQUIRED,
+	NO_LEGO_WEBSERVICE_XML,
+	LEGO_WEBSERVICE_TIMEOUT,
+	LEGO_WEBSERVICE_ERROR,
+	NO_WORLD_SERVER
+};
+
+struct Stamp {
+	eStamps type{};
+	uint32_t value{};
+	uint64_t timestamp{};
+
+	Stamp() = default;
+	Stamp(eStamps type, uint32_t value, uint64_t timestamp = time(nullptr)){
+		this->type = type;
+		this->value = value;
+		this->timestamp = timestamp;
+	}
+
+	void Serialize(RakNet::BitStream& outBitStream) const;
+	bool Deserialize(RakNet::BitStream& inBitStream);
+};
+
+
+enum class Language : uint32_t {
+	en_US,
+	pl_US,
+	de_DE,
+	en_GB,
+};
+
 struct ChatMessage {
 	uint8_t chatChannel = 0;
 	uint16_t unknown = 0;
@@ -27,6 +100,37 @@ struct ChatModerationRequest {
 };
 
 namespace ClientPackets {
+	// Server -> client. The auth server's answer to a login (the client's clientLoginResponsePacket).
+	struct LoginResponse : public LUBitStream {
+		static constexpr const char* DEFAULT_CDN_TICKET = "00000000-0000-0000-0000-000000000000";
+
+		eLoginResponse responseCode{};
+		LUString events[8]{}; // Event gating
+		uint16_t versionMajor{};
+		uint16_t versionCurrent{};
+		uint16_t versionMinor{};
+		LUWString userKey{ 33 };
+		LUString worldServerIP{ 33 };
+		LUString chatServerIP{ 33 }; // Unused
+		uint16_t worldServerPort{};
+		uint16_t chatServerPort{}; // Unused
+		LUString cdnKey{ 33 };
+		LUString cdnTicket{ DEFAULT_CDN_TICKET, 37 };
+		Language language = Language::en_US;
+		LUString localization{ "US", 3 };
+		bool justUpgradedFromF2P{}; // Written as one byte
+		bool isFreeToPlay{}; // Written as one byte
+		uint64_t freeToPlayTimeRemaining{};
+		// Written as a u16 character count followed by that many UTF-16 characters
+		std::string errorMessage{};
+		// Written after a u32 holding their size in bytes plus 4
+		std::vector<Stamp> stamps{};
+
+		LoginResponse() : LUBitStream(ServiceType::CLIENT, MessageType::Client::LOGIN_RESPONSE) {}
+		void Serialize(RakNet::BitStream& bitStream) const override;
+		bool Deserialize(RakNet::BitStream& bitStream) override;
+	};
+
 	ChatMessage HandleChatMessage(Packet* packet);
 	PositionUpdate HandleClientPositionUpdate(Packet* packet);
 	ChatModerationRequest HandleChatModerationRequest(Packet* packet);