Add GPU error handling and performance optimizations

Introduces a comprehensive GPU configuration and fallback system to resolve GPU process launch failures (Error 18), including new modules for GPU management and performance monitoring. Adds a GPU diagnostics HTML page, optimized CSS for rendering, and a diagnostic startup script. Updates main and preload scripts for improved stability, async file operations, and enhanced API exposure. Site history and bookmarks handling are optimized for performance and reliability.

preload.js

@@ -1,18 +1,79 @@
-// preload.js
+// preload.js - Optimized version
 const { contextBridge, ipcRenderer } = require('electron');
 
+// Cache DOM references for performance
+let domReady = false;
 window.addEventListener('DOMContentLoaded', () => {
+  domReady = true;
   console.log("Browser UI loaded.");
 });
 
-// stubbed preload—no-op or expose an API as needed
-contextBridge.exposeInMainWorld('electronAPI', {
-  send: (ch, ...args) => ipcRenderer.send(ch, ...args),
-  invoke: (ch, ...args) => ipcRenderer.invoke(ch, ...args),
-  on: (ch, fn) => ipcRenderer.on(ch, (e, ...args) => fn(...args))
-});
+// Optimized API exposure with error handling and caching
+const electronAPI = {
+  send: (ch, ...args) => {
+    try {
+      return ipcRenderer.send(ch, ...args);
+    } catch (err) {
+      console.error('IPC send error:', err);
+    }
+  },
+  invoke: (ch, ...args) => {
+    try {
+      return ipcRenderer.invoke(ch, ...args);
+    } catch (err) {
+      console.error('IPC invoke error:', err);
+      return Promise.reject(err);
+    }
+  },
+  on: (ch, fn) => {
+    try {
+      return ipcRenderer.on(ch, (e, ...args) => fn(...args));
+    } catch (err) {
+      console.error('IPC on error:', err);
+    }
+  },
+  // Add removeListener for cleanup
+  removeListener: (ch, fn) => {
+    try {
+      return ipcRenderer.removeListener(ch, fn);
+    } catch (err) {
+      console.error('IPC removeListener error:', err);
+    }
+  }
+};
 
-contextBridge.exposeInMainWorld('bookmarksAPI', {
-  load: () => ipcRenderer.invoke('load-bookmarks'),
-  save: (data) => ipcRenderer.invoke('save-bookmarks', data)
-});
+// Cache for bookmarks to reduce IPC calls
+let bookmarksCache = null;
+let bookmarksCacheTime = 0;
+const CACHE_DURATION = 5000; // 5 seconds
+
+const bookmarksAPI = {
+  load: async () => {
+    const now = Date.now();
+    if (bookmarksCache && (now - bookmarksCacheTime) < CACHE_DURATION) {
+      return bookmarksCache;
+    }
+    try {
+      bookmarksCache = await ipcRenderer.invoke('load-bookmarks');
+      bookmarksCacheTime = now;
+      return bookmarksCache;
+    } catch (err) {
+      console.error('Bookmarks load error:', err);
+      return [];
+    }
+  },
+  save: async (data) => {
+    try {
+      bookmarksCache = data; // Update cache immediately
+      bookmarksCacheTime = Date.now();
+      return await ipcRenderer.invoke('save-bookmarks', data);
+    } catch (err) {
+      console.error('Bookmarks save error:', err);
+      return false;
+    }
+  }
+};
+
+// Expose APIs to main world
+contextBridge.exposeInMainWorld('electronAPI', electronAPI);
+contextBridge.exposeInMainWorld('bookmarksAPI', bookmarksAPI);