Add test coverage for core server components: annotation scanning, routing, rate limiting, CORS, and JSON handling

src/test/java/dev/coph/nextusweb/server/websocket/WebSocketHandlerTest.java

@@ -0,0 +1,23 @@
+package dev.coph.nextusweb.server.websocket;
+
+import io.netty.channel.embedded.EmbeddedChannel;
+import org.junit.jupiter.api.Test;
+
+import java.util.Map;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class WebSocketHandlerTest {
+
+    @Test
+    void defaultMethodsDoNotThrow() {
+        WebSocketHandler handler = new WebSocketHandler() {};
+        EmbeddedChannel ch = new EmbeddedChannel();
+        WebSocketSession session = new WebSocketSession(ch, "/ws", Map.of());
+        assertDoesNotThrow(() -> handler.onOpen(session));
+        assertDoesNotThrow(() -> handler.onMessage(session, "msg"));
+        assertDoesNotThrow(() -> handler.onBinary(session, new byte[]{1}));
+        assertDoesNotThrow(() -> handler.onClose(session, 1000, "ok"));
+        assertDoesNotThrow(() -> handler.onError(session, new RuntimeException("e")));
+    }
+}