test(config): bind bootstrap API and public documentation

config-server/src/main/java/com/xtrmetl/config/ConfigServerApplication.java

@@ -4,9 +4,23 @@
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.cloud.config.server.EnableConfigServer;
 
+/**
+ * Starts the standalone mightyETL Config Server.
+ *
+ * <p>This bootstrap owns only starting the Spring Cloud Config server. Deployment-owned Git
+ * repository selection is a separate authority hardened by #179/#189, and inbound client
+ * authentication remains the separate security decision tracked by #193. The existence of this
+ * module does not by itself make Config Server a required/default mightyETL deployment service.</p>
+ */
 @SpringBootApplication
 @EnableConfigServer
 public class ConfigServerApplication {
+
+    /**
+     * Launches the Config Server through Spring Boot.
+     *
+     * @param args command-line arguments passed to Spring Boot
+     */
     public static void main(String[] args) {
         SpringApplication.run(ConfigServerApplication.class, args);
     }

config-server/src/test/java/com/xtrmetl/config/ConfigServerApplicationContractTest.java

@@ -0,0 +1,47 @@
+package com.xtrmetl.config;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.cloud.config.server.EnableConfigServer;
+
+import java.io.IOException;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * Verifies the standalone Config Server bootstrap contract and its beginner-readable public documentation.
+ */
+class ConfigServerApplicationContractTest {
+
+    @Test
+    void bootstrapClassKeepsTheRequiredServerAnnotations() {
+        assertNotNull(ConfigServerApplication.class.getAnnotation(SpringBootApplication.class));
+        assertNotNull(ConfigServerApplication.class.getAnnotation(EnableConfigServer.class));
+    }
+
+    @Test
+    void mainEntryPointRemainsPublicStatic() throws NoSuchMethodException {
+        Method main = ConfigServerApplication.class.getDeclaredMethod("main", String[].class);
+
+        assertTrue(Modifier.isPublic(main.getModifiers()));
+        assertTrue(Modifier.isStatic(main.getModifiers()));
+    }
+
+    @Test
+    void publicBootstrapApiHasBeginnerReadableJavadoc() throws IOException {
+        String source = Files.readString(
+                Path.of("src/main/java/com/xtrmetl/config/ConfigServerApplication.java"),
+                StandardCharsets.UTF_8
+        );
+
+        assertTrue(source.contains("Starts the standalone mightyETL Config Server"));
+        assertTrue(source.contains("Launches the Config Server through Spring Boot"));
+        assertTrue(source.contains("@param args command-line arguments passed to Spring Boot"));
+    }
+}