Add JMH data access benchmark app

src/main/java/com/benchmark/fixtures/FixtureFactory.java

@@ -0,0 +1,14 @@
+package com.benchmark.fixtures;
+
+public class FixtureFactory {
+
+    public static DataFixtures create(String type) {
+        return switch (type) {
+            case "gson"            -> new GsonFileFixture();
+            case "kryo"            -> new KryoFileFixture();
+            case "sqlite-jdbc"     -> new SqliteJdbcFixture();
+            case "sqlite-ormlite"  -> new SqliteOrmLiteFixture();
+            default -> throw new IllegalArgumentException("Unknown fixture type: " + type);
+        };
+    }
+}