Add package-info.java

src/main/java/com/ankurm/sdjpa4demo/repo/package-info.java

@@ -0,0 +1,9 @@
+/**
+ * Repositories live in a @NullMarked package. As of Spring Data 4, JSpecify's
+ * @NullMarked makes non-null the DEFAULT for parameters and return values,
+ * and Spring Data enforces it at runtime.
+ */
+@NullMarked
+package com.ankurm.sdjpa4demo.repo;
+
+import org.jspecify.annotations.NullMarked;