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.

server/src/app.ts

@@ -73,7 +73,7 @@ export async function buildApp() {
 
   fastify.get('/api/health', async () => ({
     status: 'ok',
-    version: '0.4.6',
+    version: '0.4.7',
     timestamp: new Date().toISOString(),
   }))