🎨 Add spotless formatting

gradle/spotless.gradle

@@ -0,0 +1,14 @@
+import java.nio.charset.StandardCharsets
+
+spotless {
+    enforceCheck(false)
+    ratchetFrom "origin/main"
+
+    java {
+        target "src/**/java/**/*.java"
+        encoding(StandardCharsets.UTF_8)
+        removeUnusedImports()
+        prettier(['prettier': '3.0.3', 'prettier-plugin-java': '2.3.0'])
+            .configFile('.prettierrc.yml')
+    }
+}