feat(registrystorage): Add deleteMavenMetadata to RegistryStorage and update Maven DELETE test to expect 204 No Content

ts/core/classes.registrystorage.ts

@@ -348,6 +348,17 @@ export class RegistryStorage implements IStorageBackend {
     return this.putObject(path, data);
   }
 
+  /**
+   * Delete Maven metadata (maven-metadata.xml)
+   */
+  public async deleteMavenMetadata(
+    groupId: string,
+    artifactId: string
+  ): Promise<void> {
+    const path = this.getMavenMetadataPath(groupId, artifactId);
+    return this.deleteObject(path);
+  }
+
   /**
    * List Maven versions for an artifact
    * Returns all version directories under the artifact path