Add detailed About panel to settings page

Introduces an About tab in the settings page displaying app, runtime, and system diagnostics. Adds IPC and preload bridge for about info, clipboard copy functionality, and external navigation for GitHub and Help links. Updates site-history.json with relevant links.

main.js

@@ -1,6 +1,7 @@
 const { app, BrowserWindow, ipcMain, session, screen, shell } = require('electron');
 const fs = require('fs');
 const path = require('path');
+const os = require('os');
 const PerformanceMonitor = require('./performance-monitor');
 const GPUFallback = require('./gpu-fallback');
 const GPUConfig = require('./gpu-config');
@@ -443,3 +444,29 @@ ipcMain.handle('apply-gpu-fallback', (event, level) => {
     return { error: err.message };
   }
 });
+
+// About/info handler
+ipcMain.handle('get-about-info', () => {
+  try {
+    return {
+      appName: app.getName(),
+      appVersion: app.getVersion(),
+      isPackaged: app.isPackaged,
+      appPath: app.getAppPath(),
+      userDataPath: app.getPath('userData'),
+      electronVersion: process.versions.electron,
+      chromeVersion: process.versions.chrome,
+      nodeVersion: process.versions.node,
+      v8Version: process.versions.v8,
+      platform: process.platform,
+      arch: process.arch,
+      osType: os.type(),
+      osRelease: os.release(),
+      cpu: os.cpus()?.[0]?.model || 'Unknown CPU',
+      totalMemGB: Math.round((os.totalmem() / (1024 ** 3)) * 10) / 10,
+    };
+  } catch (err) {
+    console.error('Error building about info:', err);
+    return { error: err.message };
+  }
+});