Debug: add stdout/stderr capture, log game logs to console

launcher/launcher/src/main/java/sashegdev/zernmc/launcher/api/launch/LaunchService.java

@@ -62,32 +62,38 @@ public class LaunchService {
 
             ProcessBuilder processBuilder = new ProcessBuilder(command);
             processBuilder.directory(instance.getPath().toFile());
+            processBuilder.redirectErrorStream(true);
 
             Process process = processBuilder.start();
+            System.out.println("[LAUNCH] Process started, pid=" + process.pid());
 
-            // Capture output
+            // Capture output (stdout)
             Thread outThread = new Thread(() -> {
                 try (BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()))) {
                     String line;
                     while ((line = reader.readLine()) != null) {
+                        System.out.println("[STDOUT] " + line);
                         JFXLauncher.appendGameLog(line);
                     }
                 } catch (Exception e) {
-                    JFXLauncher.appendGameLog("[Ошибка чтения вывода: " + e.getMessage() + "]");
+                    System.out.println("[STDOUT ERROR] " + e.getMessage());
+                    JFXLauncher.appendGameLog("[Ошибка чтения вывода: " + e.getMessage());
                 }
             });
             outThread.setDaemon(true);
             outThread.start();
 
-            // Capture errors
+            // Capture errors (stderr)
             Thread errThread = new Thread(() -> {
                 try (BufferedReader reader = new BufferedReader(new InputStreamReader(process.getErrorStream()))) {
                     String line;
                     while ((line = reader.readLine()) != null) {
+                        System.out.println("[STDERR] " + line);
                         JFXLauncher.appendGameLog("[ERR] " + line);
                     }
                 } catch (Exception e) {
-                    JFXLauncher.appendGameLog("[Ошибка чтения ошибок: " + e.getMessage() + "]");
+                    System.out.println("[STDERR ERROR] " + e.getMessage());
+                    JFXLauncher.appendGameLog("[Ошибка чтения ошибок: " + e.getMessage());
                 }
             });
             errThread.setDaemon(true);

launcher/launcher/src/main/java/sashegdev/zernmc/launcher/ui/jfx/JFXLauncher.java

@@ -41,6 +41,7 @@ public class JFXLauncher extends Application {
     private Stage mainStage;
 
     public static void appendGameLog(String log) {
+        System.out.println("[GAMELOG] " + log);
         synchronized (gameLogBuffer) {
             gameLogBuffer.append(log).append("\n");