feat: guard against empty terms in createGameSession

apps/api/src/services/gameService.test.ts

@@ -273,4 +273,12 @@ describe("evaluateAnswer", () => {
       ),
     ).rejects.toThrow("Game session not found");
   });
+
+  it("throws NotFoundError when getGameTerms returns no terms", async () => {
+    mockGetGameTerms.mockResolvedValue([]);
+
+    await expect(
+      createGameSession(validRequest, store, "user-1"),
+    ).rejects.toThrow("No terms found");
+  });
 });