feat(build): add gradle build system

gradle/libs.versions.toml

@@ -0,0 +1,10 @@
+# This file was generated by the Gradle 'init' task.
+# https://docs.gradle.org/current/userguide/platforms.html#sub::toml-dependencies-format
+
+[versions]
+guava = "33.2.1-jre"
+junit-jupiter = "5.10.3"
+
+[libraries]
+guava = { module = "com.google.guava:guava", version.ref = "guava" }
+junit-jupiter = { module = "org.junit.jupiter:junit-jupiter", version.ref = "junit-jupiter" }

gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,7 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.10.2-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists