fix(desktop): show the feed on startup, not a blank page

The ai-sidebar extension overrides the New Tab page with the feed
(chrome_url_overrides.newtab), but that only applies to newly opened tabs. On a
fresh launch the launcher spawned Chromium with no URL, so the first window
showed a blank/default page and the feed only appeared after opening a new tab.

launch() now defaults the startup URL to chrome://newtab/ (resolveStartUrls)
when no URLs are supplied, so the feed shows immediately. Explicit URLs are
unchanged. 3 unit tests.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: ralyodio

apps/desktop/src/launcher.test.ts

@@ -0,0 +1,21 @@
+import { describe, it, expect } from 'vitest';
+import { resolveStartUrls, DEFAULT_START_URL } from './launcher.js';
+
+describe('resolveStartUrls', () => {
+  it('opens the feed (new tab page) when no URLs are given', () => {
+    expect(resolveStartUrls()).toEqual([DEFAULT_START_URL]);
+    expect(resolveStartUrls([])).toEqual([DEFAULT_START_URL]);
+  });
+
+  it('respects explicit URLs when provided', () => {
+    expect(resolveStartUrls(['https://example.com'])).toEqual(['https://example.com']);
+    expect(resolveStartUrls(['https://a.com', 'https://b.com'])).toEqual([
+      'https://a.com',
+      'https://b.com',
+    ]);
+  });
+
+  it('defaults to the extension-overridden new tab page', () => {
+    expect(DEFAULT_START_URL).toBe('chrome://newtab/');
+  });
+});

apps/desktop/src/launcher.ts

@@ -15,10 +15,23 @@ export interface LaunchConfig extends LaunchOptions {
   urls?: string[];
 }
 
+/**
+ * The page shown on a fresh launch when no URLs are given: the extension-
+ * overridden New Tab page (the TronBrowser feed). Without an explicit startup
+ * URL, Chromium opens a blank/default page, so the `chrome_url_overrides` newtab
+ * feed only appears once the user opens a *new* tab — we open it on startup.
+ */
+export const DEFAULT_START_URL = 'chrome://newtab/';
+
+/** Resolves the URLs to open, defaulting to the feed when none are supplied. */
+export function resolveStartUrls(urls?: string[]): string[] {
+  return urls && urls.length > 0 ? urls : [DEFAULT_START_URL];
+}
+
 /** Launches the browser process with privacy flags enforced. */
 export function launch(config: LaunchConfig): ChildProcess {
   const binary = resolveBinaryPath(config.outDir, config.platform);
   const flags = buildLaunchFlags(config);
-  const args = [...flags, ...(config.urls ?? [])];
+  const args = [...flags, ...resolveStartUrls(config.urls)];
   return spawn(binary, args, { stdio: 'inherit' });
 }