Fix: NPE in AuthManager, game logs display in UI

launcher/launcher/src/main/java/sashegdev/zernmc/launcher/auth/AuthManager.java

@@ -10,6 +10,7 @@ import me.sashegdev.zernmc.launcher.utils.ZAnsi;
 import me.sashegdev.zernmc.launcher.utils.ZHttpClient;
 
 import java.io.IOException;
+import java.io.InputStream;
 import java.net.HttpURLConnection;
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
@@ -252,11 +253,15 @@ public class AuthManager {
             }
 
             int statusCode = conn.getResponseCode();
-            var is = (statusCode >= 200 && statusCode < 300) ? conn.getInputStream() : conn.getErrorStream();
+            InputStream is = (statusCode >= 200 && statusCode < 300) ? conn.getInputStream() : conn.getErrorStream();
 
             String responseBody;
-            try (var scanner = new java.util.Scanner(is, StandardCharsets.UTF_8.name())) {
-                responseBody = scanner.useDelimiter("\\A").hasNext() ? scanner.next() : "";
+            if (is != null) {
+                try (var scanner = new java.util.Scanner(is, StandardCharsets.UTF_8.name())) {
+                    responseBody = scanner.useDelimiter("\\A").hasNext() ? scanner.next() : "";
+                }
+            } else {
+                responseBody = "No response body (status " + statusCode + ")";
             }
 
             return new SimpleHttpResponse(statusCode, responseBody);

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

@@ -41,7 +41,6 @@ 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");
             
@@ -56,6 +55,9 @@ public class JFXLauncher extends Application {
     }
 
     public static void initGameLog(Path instanceDir) {
+        synchronized (gameLogBuffer) {
+            gameLogBuffer.setLength(0);
+        }
         try {
             Path logsDir = instanceDir.resolve("logs");
             Files.createDirectories(logsDir);
@@ -266,12 +268,7 @@ public class JFXLauncher extends Application {
     }
 
     private void handleGameLogs(HttpExchange exchange) {
-        String logs = getGameLogs();
-        log("[GAME-LOGS-API] Request, logs length: " + logs.length());
-        if (!logs.isEmpty()) {
-            log("[GAME-LOGS-API] First 200 chars: " + logs.substring(0, Math.min(200, logs.length())));
-        }
-        sendJson(exchange, Map.of("success", true, "data", logs));
+        sendJson(exchange, Map.of("success", true, "data", getGameLogs()));
     }
 
     private void handleExit(HttpExchange exchange) {

launcher/launcher/src/resources/ui/launcher.js

@@ -268,10 +268,8 @@ function startLogPolling() {
 
         // Game logs
         const gameResult = await apiCall('/game-logs');
-        console.log('[DEBUG] Game logs request:', gameResult.success, 'length:', gameResult.data ? gameResult.data.length : 0);
         if (gameResult.success && gameResult.data && gameResult.data.length > lastGameLogLength) {
             const newLogs = gameResult.data.substring(lastGameLogLength);
-            console.log('[DEBUG] New game logs:', newLogs.substring(0, 200));
             const lines = newLogs.split('\n').filter(l => l.trim());
             lines.forEach(line => {
                 log('[GAME] ' + line, 'info');