Add Tier 1 utility commands: ignore, sit/stand, and logout

Ignore Commands:
- Add /ignore <name> to block messages from players
- Add /unignore <name> to unblock players
- Maintain ignoreCache for name-to-GUID lookups
- Show confirmation and error messages for ignore actions
- Use CMSG_ADD_IGNORE (0x6C) and CMSG_DEL_IGNORE (0x6D)

Sit/Stand/Kneel Commands:
- Add /sit to sit down (stand state 1)
- Add /stand to stand up (stand state 0)
- Add /kneel to kneel (stand state 8)
- Instant visual feedback with CMSG_STAND_STATE_CHANGE (0x101)
- Support for additional stand states (chair, sleep, etc.)

Logout Commands:
- Add /logout and /camp to initiate logout with countdown
- Add /cancellogout to cancel pending logout
- Show "Logging out in 20 seconds..." or "Logout complete" messages
- Track logout state with loggingOut_ flag to prevent duplicate requests
- Handle instant logout (in inn/city) vs countdown logout
- Use opcodes:
  - CMSG_LOGOUT_REQUEST (0x4B)
  - CMSG_LOGOUT_CANCEL (0x4E)
  - SMSG_LOGOUT_RESPONSE (0x4C)
  - SMSG_LOGOUT_COMPLETE (0x4D)

Implementation:
- Add LogoutRequestPacket, LogoutCancelPacket builders
- Add LogoutResponseParser to parse server logout responses
- Add StandStateChangePacket builder for stance changes
- Add AddIgnorePacket and DelIgnorePacket for ignore list management
- Add handleLogoutResponse() and handleLogoutComplete() handlers
- Add ignoreCache map and loggingOut_ state tracking
- All commands display feedback in chat window

src/ui/game_screen.cpp

@@ -1079,6 +1079,77 @@ void GameScreen::sendChatMessage(game::GameHandler& gameHandler) {
                 return;
             }
 
+            // /ignore command
+            if (cmdLower == "ignore") {
+                if (spacePos != std::string::npos) {
+                    std::string playerName = command.substr(spacePos + 1);
+                    gameHandler.addIgnore(playerName);
+                    chatInputBuffer[0] = '\0';
+                    return;
+                }
+
+                game::MessageChatData msg;
+                msg.type = game::ChatType::SYSTEM;
+                msg.language = game::ChatLanguage::UNIVERSAL;
+                msg.message = "Usage: /ignore <name>";
+                gameHandler.addLocalChatMessage(msg);
+                chatInputBuffer[0] = '\0';
+                return;
+            }
+
+            // /unignore command
+            if (cmdLower == "unignore") {
+                if (spacePos != std::string::npos) {
+                    std::string playerName = command.substr(spacePos + 1);
+                    gameHandler.removeIgnore(playerName);
+                    chatInputBuffer[0] = '\0';
+                    return;
+                }
+
+                game::MessageChatData msg;
+                msg.type = game::ChatType::SYSTEM;
+                msg.language = game::ChatLanguage::UNIVERSAL;
+                msg.message = "Usage: /unignore <name>";
+                gameHandler.addLocalChatMessage(msg);
+                chatInputBuffer[0] = '\0';
+                return;
+            }
+
+            // /sit command
+            if (cmdLower == "sit") {
+                gameHandler.setStandState(1);  // 1 = sit
+                chatInputBuffer[0] = '\0';
+                return;
+            }
+
+            // /stand command
+            if (cmdLower == "stand") {
+                gameHandler.setStandState(0);  // 0 = stand
+                chatInputBuffer[0] = '\0';
+                return;
+            }
+
+            // /kneel command
+            if (cmdLower == "kneel") {
+                gameHandler.setStandState(8);  // 8 = kneel
+                chatInputBuffer[0] = '\0';
+                return;
+            }
+
+            // /logout command (already exists but using /logout instead of going to login)
+            if (cmdLower == "logout" || cmdLower == "camp") {
+                gameHandler.requestLogout();
+                chatInputBuffer[0] = '\0';
+                return;
+            }
+
+            // /cancellogout command
+            if (cmdLower == "cancellogout") {
+                gameHandler.cancelLogout();
+                chatInputBuffer[0] = '\0';
+                return;
+            }
+
             // Chat channel slash commands
             bool isChannelCommand = false;
             if (cmdLower == "s" || cmdLower == "say") {