feat: Ending model + endings.yaml loading (ordered, optional)

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

Semesterprojekt/src/test/java/thb/jeanluc/adventure/loader/EndingLoadingTest.java

@@ -0,0 +1,22 @@
+package thb.jeanluc.adventure.loader;
+
+import org.junit.jupiter.api.Test;
+import thb.jeanluc.adventure.loader.dto.ConditionDto;
+import thb.jeanluc.adventure.loader.dto.EndingDto;
+import thb.jeanluc.adventure.model.Ending;
+
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class EndingLoadingTest {
+    @Test
+    void factoryMapsFields() {
+        Ending e = EndingFactory.fromDto(new EndingDto("victory", "Won", true,
+                List.of(new ConditionDto("manor_secured", null, null)), "You win."));
+        assertThat(e.id()).isEqualTo("victory");
+        assertThat(e.victory()).isTrue();
+        assertThat(e.when()).hasSize(1);
+        assertThat(e.text()).isEqualTo("You win.");
+    }
+}