chore: bump version to v2.8.4

Bump the dashboard package version for the latest skills layout fix and prepare the repository for the v2.8.4 release.

Author: leolionart

frontend/package-lock.json

@@ -1,7 +1,7 @@
 {
     "name": "cliproxy-dashboard",
     "private": true,
-    "version": "2.8.3",
+    "version": "2.8.4",
     "type": "module",
     "scripts": {
         "dev": "vite",