Add Gantt users styling and adjust layout in main view

- Introduced a new flexbox layout for .gantt_users with a gap of 20px in style.scss.
- Moved the gantt-target div to the end of the projects_container for better layout consistency.
- Adjusted the margin-bottom of projects_container for improved spacing.

.vscode/ftp-kr.sync.cache.json

@@ -139,8 +139,8 @@
           },
           "class.Tasks.php": {
             "type": "-",
-            "size": 18435,
-            "lmtime": 1744498887425,
+            "size": 18467,
+            "lmtime": 1744570592304,
             "modified": false
           },
           "class.Users.php": {