refactor(app): drop dead newSession param, unused import, restore main javadoc

- Remove unused `saves` parameter from `newSession(GameIO, SaveService)`
  → signature is now `newSession(GameIO)`, call site updated accordingly
- Remove unused `import thb.jeanluc.adventure.menu.MenuAction` (switch
  uses unqualified constants; import was dead, compile confirmed clean)
- Restore `/** Standard JVM entry point. @param args ignored */` Javadoc
  on `main` and restore full log message "Fatal error during game startup"

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Semesterprojekt/src/main/java/thb/jeanluc/adventure/App.java

@@ -26,7 +26,6 @@ import thb.jeanluc.adventure.io.GameIO;
 import thb.jeanluc.adventure.io.text.Banner;
 import thb.jeanluc.adventure.loader.WorldLoader;
 import thb.jeanluc.adventure.menu.MainMenu;
-import thb.jeanluc.adventure.menu.MenuAction;
 import thb.jeanluc.adventure.menu.SettingsMenu;
 import thb.jeanluc.adventure.save.SaveException;
 import thb.jeanluc.adventure.save.SaveService;
@@ -48,12 +47,13 @@ public final class App {
     private App() {
     }
 
+    /** Standard JVM entry point. @param args ignored */
     public static void main(String[] args) {
         GameIO io = new ConsoleIO();
         try {
             run(io);
         } catch (RuntimeException e) {
-            log.error("Fatal error", e);
+            log.error("Fatal error during game startup", e);
             io.write("Fatal error: " + e.getMessage());
             System.exit(1);
         }
@@ -70,7 +70,7 @@ public final class App {
         boolean running = true;
         while (running) {
             switch (MainMenu.show(io)) {
-                case NEW_GAME -> play(io, saves, newSession(io, saves));
+                case NEW_GAME -> play(io, saves, newSession(io));
                 case LOAD -> {
                     SaveSlotInfo slot = MainMenu.pickSlot(io, saves);
                     if (slot != null) {
@@ -89,7 +89,7 @@ public final class App {
     }
 
     /** Loads a fresh world and binds it to a newly named session. */
-    private static GameSession newSession(GameIO io, SaveService saves) {
+    private static GameSession newSession(GameIO io) {
         WorldLoader.LoadResult loaded = new WorldLoader().load();
         String name = MainMenu.promptName(io, "Manor");
         return new GameSession(loaded.world(), loaded.player(), name);