feat(game): QuestEngine (auto-advance + announcements) and QuestView

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Semesterprojekt/src/test/java/thb/jeanluc/adventure/game/QuestEngineTest.java

@@ -0,0 +1,63 @@
+package thb.jeanluc.adventure.game;
+
+import org.junit.jupiter.api.Test;
+import thb.jeanluc.adventure.io.TestIO;
+import thb.jeanluc.adventure.io.text.QuestView;
+import thb.jeanluc.adventure.model.Condition;
+import thb.jeanluc.adventure.model.Effect;
+import thb.jeanluc.adventure.model.Player;
+import thb.jeanluc.adventure.model.Quest;
+import thb.jeanluc.adventure.model.QuestStage;
+import thb.jeanluc.adventure.model.Room;
+import thb.jeanluc.adventure.model.World;
+
+import java.util.List;
+import java.util.Map;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class QuestEngineTest {
+    private GameContext ctx(Quest quest) {
+        Player p = new Player(new Room("k", "K", "d"), 0);
+        World w = new World(Map.of(), Map.of(), Map.of(), "t", "w", Map.of(quest.id(), quest));
+        return new GameContext(w, p, new TestIO());
+    }
+
+    private Quest twoStage() {
+        return new Quest("q", "Quest", true, List.of(
+                new QuestStage("Stage one", List.of(new Condition(Condition.Type.FLAG, "a")), List.of()),
+                new QuestStage("Stage two", List.of(new Condition(Condition.Type.FLAG, "b")),
+                        List.of(new Effect(Effect.Type.SET_FLAG, "done")))), List.of());
+    }
+
+    @Test
+    void autoStartsAndShowsFirstObjective() {
+        GameContext ctx = ctx(twoStage());
+        QuestEngine.tick(ctx);
+        QuestView v = QuestEngine.viewOf(ctx);
+        assertThat(v.active()).hasSize(1);
+        assertThat(v.active().getFirst().objective()).isEqualTo("Stage one");
+    }
+
+    @Test
+    void advancesWhenConditionHolds() {
+        GameContext ctx = ctx(twoStage());
+        QuestEngine.tick(ctx);
+        ctx.getState().set("a");
+        QuestEngine.tick(ctx);
+        assertThat(QuestEngine.viewOf(ctx).active().getFirst().objective()).isEqualTo("Stage two");
+        assertThat(((TestIO) ctx.getIo()).allOutput()).contains("Objective complete");
+    }
+
+    @Test
+    void completesAfterLastStageAndAppliesReward() {
+        GameContext ctx = ctx(twoStage());
+        ctx.getState().set("a");
+        ctx.getState().set("b");
+        QuestEngine.tick(ctx); // cascades through both stages in one tick
+        QuestView v = QuestEngine.viewOf(ctx);
+        assertThat(v.active()).isEmpty();
+        assertThat(v.completed()).containsExactly("Quest");
+        assertThat(ctx.getState().isSet("done")).isTrue();
+    }
+}