Fix file browser for directories two levels deep

TreeWalk was only entering exact-match subtrees, missing intermediate
directories. Now enters all subtrees that are prefix of the target path.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/main/java/be/seeseepuff/webgit/service/GitService.java

@@ -464,13 +464,15 @@ public class GitService
 					if (dirPath != null && !dirPath.isEmpty())
 					{
 						tw.setFilter(PathFilter.create(dirPath));
-						// Walk into the directory
+						// Walk into the directory, entering intermediate subtrees as needed
 						while (tw.next())
 						{
-							if (tw.isSubtree() && tw.getPathString().equals(dirPath))
+							if (tw.isSubtree())
 							{
+								String path = tw.getPathString();
 								tw.enterSubtree();
-								break;
+								if (path.equals(dirPath))
+									break;
 							}
 						}
 					}