Improve Steam Input handling and update documentation

Updated main.js to better manage Steam Input environment variables, explicitly initialize and shutdown Steam Input, and regularly pump Steam callbacks to ensure proper controller support. Enhanced README-STEAM.md with detailed instructions for configuring Steam Input on Windows, Linux, and Steam Deck, including guidance for software/app limitations and launch options.

main.js

@@ -15,7 +15,10 @@ process.env.SDL_GAMECONTROLLERCONFIG = process.env.SDL_GAMECONTROLLERCONFIG || '
 
 // Signal that this app handles gamepad input natively
 // This prevents Steam from applying mouse emulation in Game Mode
-process.env.SDL_GAMECONTROLLER_ALLOW_STEAM_VIRTUAL_GAMEPAD = '1';
+// IMPORTANT: set to 0 to avoid Steam's virtual gamepad layer when possible.
+// Forcing this to 1 can keep Steam virtualization/emulation active.
+process.env.SDL_GAMECONTROLLER_ALLOW_STEAM_VIRTUAL_GAMEPAD =
+  process.env.SDL_GAMECONTROLLER_ALLOW_STEAM_VIRTUAL_GAMEPAD ?? '0';
 
 // Prevent Steam from remapping the controller to keyboard/mouse
 // Setting to '1' tells Steam we want raw controller access
@@ -26,9 +29,8 @@ process.env.SteamNoOverlayUIDrawing = process.env.SteamNoOverlayUIDrawing || '0'
 
 // Tell Steam Input we're a native controller app
 // When STEAM_INPUT_ENABLE_VIRTUAL_GAMEPAD is 0, Steam won't virtualize the gamepad
-if (!process.env.STEAM_INPUT_ENABLE_VIRTUAL_GAMEPAD) {
-  process.env.STEAM_INPUT_ENABLE_VIRTUAL_GAMEPAD = '0';
-}
+process.env.STEAM_INPUT_ENABLE_VIRTUAL_GAMEPAD =
+  process.env.STEAM_INPUT_ENABLE_VIRTUAL_GAMEPAD ?? '0';
 
 // Hint that this is a game/controller-focused app
 process.env.SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS = '1';
@@ -48,10 +50,13 @@ process.env.SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS = '1';
 let steamworksClient = null;
 let steamworksInitialized = false;
 let steamInput = null;
+let steamworksModule = null;
+let steamCallbacksInterval = null;
 
 function initializeSteamworks() {
   try {
     const steamworks = require('steamworks.js');
+    steamworksModule = steamworks;
     
     // Initialize with Nebula's Steam App ID
     steamworksClient = steamworks.init(4290110);
@@ -67,6 +72,27 @@ function initializeSteamworks() {
       steamInput = steamworksClient.input;
       if (steamInput) {
         console.log('[Steamworks] Steam Input API available - native controller mode enabled');
+
+        // Explicitly initialize Steam Input.
+        // Also ensure Steam callbacks are pumped; Steamworks features (including input)
+        // depend on runCallbacks being called regularly.
+        try {
+          if (typeof steamInput.init === 'function') {
+            steamInput.init();
+          }
+        } catch (initErr) {
+          console.log('[Steamworks] Steam Input init failed:', initErr.message);
+        }
+
+        if (!steamCallbacksInterval && typeof steamworks.runCallbacks === 'function') {
+          steamCallbacksInterval = setInterval(() => {
+            try {
+              steamworks.runCallbacks();
+            } catch {
+              // Ignore callback pump errors to avoid crashing the app.
+            }
+          }, 100);
+        }
         
         // Try to get connected controllers to verify input is working
         try {
@@ -101,6 +127,19 @@ function initializeSteamworks() {
 // This is critical for Steam Input to recognize native controller support
 initializeSteamworks();
 
+// Cleanup Steam callback pump on exit
+try {
+  app?.once?.('before-quit', () => {
+    if (steamCallbacksInterval) {
+      clearInterval(steamCallbacksInterval);
+      steamCallbacksInterval = null;
+    }
+    try {
+      steamInput?.shutdown?.();
+    } catch {}
+  });
+} catch {}
+
 const { app, BrowserWindow, ipcMain, session, screen, shell, dialog, Menu, clipboard, webContents } = require('electron');
 const { autoUpdater } = require('electron-updater');
 const { pathToFileURL } = require('url');