fix(backend): Starter zip file entries being created with leadin (dotCMS#32249) (dotCMS#32250)

### Proposed Changes
* Minimal fix for path issue causing leading slash in starter zip assets
entries

### Checklist
- [ ] Tests
- [ ] Translations
- [ ] Security Implications Contemplated (add notes if applicable)


### Testing
* Download a starter from the Maintenance page
* Use "unzip -l {starter filename}" to list the file paths, ensure that
non start with a /


### Additional Info
This PR resolves dotCMS#32249 (Starter zip file entries being created with
leadin).


### Screenshots
Original             |  Updated
:-------------------------:|:-------------------------:
** original screenshot **  |  ** updated screenshot **

Author: spbolton

dotCMS/src/main/java/com/dotmarketing/util/starter/ExportStarterUtil.java

@@ -67,6 +67,7 @@
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
+import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.sql.Connection;
 import java.sql.PreparedStatement;
@@ -118,7 +119,7 @@ public class ExportStarterUtil {
     private static final Lazy<Integer> QUEUE_CAPACITY =
             Lazy.of(() -> Config.getIntProperty(STARTER_GENERATION_QUEUE_CAPACITY_PROP, 1000));
     private static final Lazy<String> ZIP_FILE_ASSETS_FOLDER =
-            Lazy.of(() -> Config.getStringProperty(STARTER_GENERATION_ASSETS_FOLDER_PROP, "/assets/"));
+            Lazy.of(() -> Config.getStringProperty(STARTER_GENERATION_ASSETS_FOLDER_PROP, "assets"));
 
     private static final String JSON_FILE_EXT = ".json";
 
@@ -484,10 +485,28 @@ private void addFolderToZip(final ZipOutputStream zip, final FileFilter fileFilt
             return;
         }
         FileUtil.listFilesRecursively(source, fileFilter).stream().filter(File::isFile).forEach(file -> {
-            final String filePath = file.getPath().replace(ConfigUtils.getAssetPath(), ZIP_FILE_ASSETS_FOLDER.get());
-            Logger.debug(this, String.format("-> File path: %s", filePath));
-            final FileEntry entry = new FileEntry(filePath, file);
-            this.addFileToZip(entry, zip);
+            try {
+                Path sourcePath = Paths.get(ConfigUtils.getAssetPath()).normalize();
+                Path currentFilePath = file.toPath().normalize();
+                Path targetFolderPath = Paths.get(ZIP_FILE_ASSETS_FOLDER.get()).normalize();
+
+                // Get relative path from source to current file
+                Path relativePath = sourcePath.relativize(currentFilePath);
+
+                // Construct the final path by combining target folder with relative path
+                Path finalPath = targetFolderPath.resolve(relativePath);
+
+                // Convert to string with forward slashes for ZIP compatibility
+                String filePath = finalPath.toString().replace('\\', '/');
+
+                Logger.debug(this, String.format("-> File path: %s", filePath));
+                final FileEntry entry = new FileEntry(filePath, file);
+                this.addFileToZip(entry, zip);
+
+            } catch (Exception e) {
+                Logger.error(this, String.format("Error processing file path for %s: %s",
+                        file.getPath(), e.getMessage()));
+            }
         });