Add --debugger command line flag to enable the WebSocket debugger

Application-mode only (CmdLineMode::Application) - the headless build has
its own separate --debugger=PORT mechanism in headless/Headless.cpp, which
doesn't currently work reliably, so this new flag intentionally does not
apply there. Sets bRemoteDebuggerOnStartup for the session without
persisting it to the config file.

Co-Authored-By: Claude Opus 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01XDNwPPuidmNxQGRJxBuRL6

Core/CmdLine.cpp

@@ -139,6 +139,7 @@ static const CommandLineParam g_autoParams[] = {
 	{POFF(startScreen), CmdParamType::String, "start-screen", '\0', "Start on a specific screen (e.g. 'gamesettings', 'touchscreentest')", CmdLineMode::Application},
 	{POFF(escapeExit), CmdParamType::Bool, "escape-exit", '\0', "Escape key exits the application", CmdLineMode::Application},
 	{POFF(pauseMenuExit), CmdParamType::Bool, "pause-menu-exit", '\0', "Change \"Exit to menu\" in pause menu to \"Exit\"", CmdLineMode::Application},
+	{POFF(enableDebugger), CmdParamType::Bool, "debugger", '\0', "Enable the WebSocket debugger on startup (see docs/WebSocketDebugger.md)", CmdLineMode::Application},
 	{POFF(appendConfig), CmdParamType::String, "appendconfig", '\0', "Merge config FILE into the current configuration"},
 	{POFF(root), CmdParamType::String, "root", 'r', "Mount root directory"},
 	{POFF(stateToLoad), CmdParamType::String, "state", '\0', "Load state from specified file"},
@@ -395,6 +396,11 @@ void CommandLineOptions::ApplyToConfig() const {
 		g_Config.bPauseMenuExitsEmulator = pauseMenuExit.value();
 	}
 
+	if (enableDebugger.has_value()) {
+		g_Config.bRemoteDebuggerOnStartup = enableDebugger.value();
+		g_Config.DoNotSaveSetting(&g_Config.bRemoteDebuggerOnStartup);
+	}
+
 	if (logLevel.has_value()) {
 		g_logManager.SetAllLogLevels(logLevel.value());
 	}

Core/CmdLine.h

@@ -40,6 +40,9 @@ struct CommandLineOptions {
 	std::optional<bool> escapeExit;
 	std::optional<bool> pauseMenuExit;
 
+	// Enables the WebSocket debugger on startup (Application mode only - see docs/WebSocketDebugger.md).
+	std::optional<bool> enableDebugger;
+
 	std::optional<std::string> appendConfig;
 	std::optional<std::string> root;  // mount root, needs more explanation
 	std::optional<std::string> stateToLoad;