feat: initialize project structure with Gradle and Spring Boot setup

settings.gradle.kts

@@ -0,0 +1,14 @@
+pluginManagement {
+    repositories {
+        gradlePluginPortal()
+        mavenCentral()
+    }
+}
+
+dependencyResolutionManagement {
+    repositories {
+        mavenCentral()
+    }
+}
+
+rootProject.name = "delta-force-guide-server"