Prevent NPE when record data starts with magic byte but no registry set

.gitignore

@@ -3,6 +3,10 @@
 # Maven build targets
 target/
 
+# NPM dependencies and build output
+node_modules/
+dist/
+
 # Maven release files
 *.releaseBackup
 release.properties

api/src/main/java/com/github/streamshub/console/api/support/serdes/MultiformatDeserializer.java

@@ -196,13 +196,13 @@ public RecordData deserialize(String topic, Headers headers, byte[] data) {
             }
         }
 
+        var idHandler = baseSerde.getIdHandler();
         ByteBuffer buffer;
         SchemaLookupResult<Object> schema;
         int length;
 
-        if (data.length > 0 && data[0] == BaseSerde.MAGIC_BYTE) {
+        if (data.length > 0 && data[0] == BaseSerde.MAGIC_BYTE && idHandler != null) {
             buffer = BaseSerde.getByteBuffer(data);
-            var idHandler = baseSerde.getIdHandler();
             artifactReference = idHandler.readId(buffer);
             schema = resolve(artifactReference);
             length = buffer.limit() - idHandler.idSize() - 1;

api/src/test/java/com/github/streamshub/console/api/RecordsResourceIT.java

@@ -91,6 +91,7 @@ class RecordsResourceIT {
     RecordHelper recordUtils;
     String clusterId1;
     String clusterId3;
+    String clusterIdY = "test-kafkaY";
 
     @BeforeEach
     void setup() {
@@ -473,6 +474,24 @@ void testConsumeRecordWithOffsetBeforeBeginning() {
             .body("data[0].attributes.value", is(equalTo("fourth")));
     }
 
+    @Test
+    void testConsumeRecordMagicByteWithoutRegistry() {
+        final String topicName = UUID.randomUUID().toString();
+        var topicIds = topicUtils.createTopics(List.of(topicName), 1);
+        recordUtils.produceRecord(topicName, null, null, null, "\u0000rest of value");
+
+        await().atMost(5, TimeUnit.SECONDS)
+            .until(() -> topicUtils.getTopicSize(topicName) == 1);
+
+        whenRequesting(req -> req
+                .get("", clusterIdY, topicIds.get(topicName)))
+            .assertThat()
+            .statusCode(is(Status.OK.getStatusCode()))
+            .body("data", hasSize(1))
+            .body("data[0].attributes.offset", is(equalTo(0)))
+            .body("data[0].attributes.value", is(equalTo("\u0000rest of value")));
+    }
+
     @Test
     void testConsumeRecordFromTimestampAcrossPartitions() {
         final String topicName = UUID.randomUUID().toString();