fix: regenerate package-lock.json after @nixpanel/whm → @nixpanel/nixserver rename, bump v0.4.7

The old package-lock.json still referenced @nixpanel/whm as a workspace.
After the package rename in v0.4.6, npm install failed to resolve the
workspace correctly, causing the nixserver frontend build to fail and
breaking login. Deleted and regenerated package-lock.json cleanly.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "nixpanel-server",
-  "version": "0.4.6",
+  "version": "0.4.7",
   "private": true,
   "workspaces": [
     "server",