feat: sentry integration (#51)

* feat: integrate sentry error reporting

* feat: report logger errors to sentry with 30s log context

src/preload.ts

@@ -1,6 +1,44 @@
 import { ipcRenderer, contextBridge } from 'electron';
+import * as Sentry from '@sentry/electron/renderer';
 import { IPC_CHANNELS } from './constants';
 
+import path from 'path';
+import fs from 'fs';
+import os from 'os';
+
+// Config check logic (duplicate of instrument.ts logic but adapted for preload)
+let sentryEnabled = false;
+try {
+  const home = os.homedir();
+  let appDataPath = '';
+  if (process.platform === 'win32') {
+    appDataPath = path.join(
+      process.env.APPDATA || path.join(home, 'AppData', 'Roaming'),
+      'Antigravity',
+    );
+  } else if (process.platform === 'darwin') {
+    appDataPath = path.join(home, 'Library', 'Application Support', 'Antigravity');
+  } else {
+    appDataPath = path.join(home, '.config', 'Antigravity');
+  }
+
+  const configPath = path.join(appDataPath, 'gui_config.json');
+  if (fs.existsSync(configPath)) {
+    const content = fs.readFileSync(configPath, 'utf-8');
+    const config = JSON.parse(content);
+    sentryEnabled = config.error_reporting_enabled === true;
+  }
+} catch (e) {
+  // console.error('Preload: Failed to read config', e);
+}
+
+if (sentryEnabled) {
+  // Defer Sentry init to avoid blocking main thread during startup (white screen fix)
+  setTimeout(() => {
+    // console.log('[Preload] Initializing Sentry (Deferred)');
+    Sentry.init({});
+  }, 2000);
+}
 window.addEventListener('message', (event) => {
   if (event.data === IPC_CHANNELS.START_ORPC_SERVER) {
     const [serverPort] = event.ports;
@@ -10,6 +48,7 @@ window.addEventListener('message', (event) => {
 });
 
 contextBridge.exposeInMainWorld('electron', {
+  SENTRY_ENABLED: sentryEnabled,
   onGoogleAuthCode: (callback: (code: string) => void) => {
     const handler = (_event: any, code: string) => callback(code);
     ipcRenderer.on('GOOGLE_AUTH_CODE', handler);