fix: recursive data nesting guard + VM destroy in uninstall wizard

- Cleaned 242MB of recursive data/data/data/ nesting
- Added nesting-guard.js: auto-detects and removes recursive duplicates at startup
- Wired VM sandbox cleanup into uninstall wizard (calls vmDestroy before regular uninstall)
- Container stats, health data, and VM disk all cleaned on uninstall

dashcaddy-installer/src/preload/index.js

@@ -113,6 +113,16 @@ contextBridge.exposeInMainWorld('electronAPI', {
     ipcRenderer.on('vm:error', (event, data) => callback(data));
   },
 
+  // --- Auto-updater ---
+  checkForUpdates: () => ipcRenderer.invoke('check-for-updates'),
+  quitAndInstall: () => ipcRenderer.invoke('quit-and-install'),
+  onUpdateAvailable: (callback) => {
+    ipcRenderer.on('update-available', (event, data) => callback(data));
+  },
+  onUpdateDownloaded: (callback) => {
+    ipcRenderer.on('update-downloaded', (event, data) => callback(data));
+  },
+
   // Remove listeners
   removeListener: (channel) => {
     ipcRenderer.removeAllListeners(channel);