Migrate FightSystem modes and countdowns to GameCore

- Move shared arena-mode abstractions into GameCore
- Adapt fight countdowns and APIs to the shared model
- Add SteamWar issue audit workflow and SQL language settings

TowerRun/src/de/steamwar/towerrun/countdowns/Countdown.java

@@ -23,18 +23,14 @@ import de.steamwar.towerrun.TowerRun;
 import de.steamwar.towerrun.state.GameStateToggleListener;
 import de.steamwar.towerrun.state.GameStates;
 import lombok.Getter;
-import lombok.Setter;
-import org.bukkit.Bukkit;
-import org.bukkit.scheduler.BukkitTask;
 
 import java.util.EnumSet;
 
 public abstract class Countdown extends GameStateToggleListener {
 
-    @Setter
     @Getter
     protected int time = defaultTime();
-    protected BukkitTask task;
+    private de.steamwar.gamecore.countdown.Countdown countdown;
 
     protected Countdown(EnumSet<GameStates> enabledStates) {
         super(enabledStates);
@@ -60,30 +56,48 @@ public abstract class Countdown extends GameStateToggleListener {
     void timerReset() {
     }
 
-    private void timer() {
-        if (timerShouldCancel()) {
-            time = defaultTime();
-            timerReset();
-        } else {
-            if (time == defaultTime()) {
-                timerStart();
-            }
-            if (time == 0) {
-                timerEnd();
-                return;
-            }
-            run();
-            time--;
+    public void setTime(int time) {
+        this.time = time;
+        if (countdown != null) {
+            countdown.setRemainingTime(time + 1);
         }
     }
 
     @Override
     public void enable() {
-        task = Bukkit.getScheduler().runTaskTimer(TowerRun.getInstance(), this::timer, 0, 20);
+        countdown = new de.steamwar.gamecore.countdown.Countdown(
+                TowerRun.getInstance(), defaultTime() + 1, 0, 20, false
+        ) {
+            @Override
+            protected void onTick(int remaining) {
+                time = remaining;
+                if (timerShouldCancel()) {
+                    reset();
+                    time = defaultTime();
+                    timerReset();
+                    return;
+                }
+                if (time == defaultTime()) {
+                    timerStart();
+                }
+                if (time > 0) {
+                    run();
+                }
+            }
+
+            @Override
+            protected void onFinished() {
+                timerEnd();
+            }
+        };
+        countdown.enable();
     }
 
     @Override
     public void disable() {
-        task.cancel();
+        if (countdown != null) {
+            countdown.disable();
+            countdown = null;
+        }
     }
 }