fix: Better electron handling (#695)

### TL;DR

Refactored the Electron main process code to improve organization and error handling.

### What changed?

- Split monolithic `index.ts` into smaller, focused modules:
  - `window.ts` - Window creation and management
  - `menu.ts` - Application menu building
  - `deep-links.ts` - Deep link handling
- Improved error handling for uncaught exceptions and unhandled rejections
- When the main window is closed, we now shut the application down entirely

Author: charlesvien

apps/twig/src/main/bootstrap.ts

@@ -6,31 +6,29 @@
  * instantiation (which calls app.getPath('userData') in their constructors).
  *
  */
-import { existsSync, renameSync } from "node:fs";
+
+import dns from "node:dns";
 import path from "node:path";
 import { app } from "electron";
+import { fixPath } from "./lib/fixPath.js";
 
 const isDev = !app.isPackaged;
 
-// Set different app names for separate single-instance locks
-const legacyAppName = isDev ? "array-dev" : "Array";
+// Set app name for single-instance lock, crashReporter, etc
 const appName = isDev ? "twig-dev" : "Twig";
 app.setName(isDev ? "Twig (Development)" : "Twig");
 
-// Migrate userData from legacy location if needed
+// Set userData path for @posthog/twig
 const appDataPath = app.getPath("appData");
-const legacyUserDataPath = path.join(appDataPath, "@posthog", legacyAppName);
 const userDataPath = path.join(appDataPath, "@posthog", appName);
+app.setPath("userData", userDataPath);
 
-if (existsSync(legacyUserDataPath) && !existsSync(userDataPath)) {
-  try {
-    renameSync(legacyUserDataPath, userDataPath);
-  } catch {
-    // If migration fails, continue with new path
-  }
-}
+// Force IPv4 resolution when "localhost" is used so the agent hits 127.0.0.1
+// instead of ::1. This matches how the renderer already reaches the PostHog API.
+dns.setDefaultResultOrder("ipv4first");
 
-app.setPath("userData", userDataPath);
+// Call fixPath early to ensure PATH is correct for any child processes
+fixPath();
 
 // Now dynamically import the rest of the application
 // Dynamic import ensures the path is set BEFORE index.js is evaluated

apps/twig/src/main/deep-links.ts

@@ -0,0 +1,65 @@
+import { app } from "electron";
+import { container } from "./di/container.js";
+import { MAIN_TOKENS } from "./di/tokens.js";
+import type { DeepLinkService } from "./services/deep-link/service.js";
+import { focusMainWindow } from "./window.js";
+
+let pendingDeepLinkUrl: string | null = null;
+
+function getDeepLinkService(): DeepLinkService {
+  return container.get<DeepLinkService>(MAIN_TOKENS.DeepLinkService);
+}
+
+/**
+ * Register app-level deep link event handlers.
+ * Must be called before app.whenReady() so macOS open-url events are captured.
+ */
+export function registerDeepLinkHandlers(): void {
+  // Handle deep link URLs on macOS
+  app.on("open-url", (event, url) => {
+    event.preventDefault();
+
+    if (!app.isReady()) {
+      pendingDeepLinkUrl = url;
+      return;
+    }
+
+    getDeepLinkService().handleUrl(url);
+    focusMainWindow();
+  });
+
+  // Handle deep link URLs on Windows/Linux (second instance sends URL via command line)
+  app.on("second-instance", (_event, commandLine) => {
+    const url = commandLine.find(
+      (arg) => arg.startsWith("twig://") || arg.startsWith("array://"),
+    );
+    if (url) {
+      getDeepLinkService().handleUrl(url);
+    }
+
+    focusMainWindow();
+  });
+}
+
+/**
+ * Register the deep link protocol and process any URLs that arrived before
+ * the app was ready.
+ * Must be called after app.whenReady().
+ */
+export function initializeDeepLinks(): void {
+  getDeepLinkService().registerProtocol();
+
+  if (process.platform === "darwin") {
+    if (pendingDeepLinkUrl) {
+      getDeepLinkService().handleUrl(pendingDeepLinkUrl);
+      pendingDeepLinkUrl = null;
+    }
+  } else {
+    const deepLinkUrl = process.argv.find(
+      (arg) => arg.startsWith("twig://") || arg.startsWith("array://"),
+    );
+    if (deepLinkUrl) {
+      getDeepLinkService().handleUrl(deepLinkUrl);
+    }
+  }
+}