feat(io): GameIO.choose numbered-menu primitive (console default)

Semesterprojekt/src/test/java/thb/jeanluc/adventure/io/ChooseDefaultTest.java

@@ -0,0 +1,32 @@
+package thb.jeanluc.adventure.io;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class ChooseDefaultTest {
+
+    @Test
+    void returnsZeroBasedIndexOfValidChoice() {
+        TestIO io = new TestIO().enqueue("2");
+        int i = io.choose("Menu", List.of("A", "B", "C"));
+        assertThat(i).isEqualTo(1);
+    }
+
+    @Test
+    void rePromptsOnInvalidThenAccepts() {
+        TestIO io = new TestIO().enqueue("9").enqueue("x").enqueue("1");
+        int i = io.choose("Menu", List.of("A", "B"));
+        assertThat(i).isZero();
+        assertThat(io.allOutput()).contains("between 1 and 2");
+    }
+
+    @Test
+    void eofReturnsLastOption() {
+        TestIO io = new TestIO(); // empty queue → readLine() returns null
+        int i = io.choose("Menu", List.of("Play", "Quit"));
+        assertThat(i).isEqualTo(1);
+    }
+}