Add OpenRouter to setup banner (#1242)

<!-- This is an auto-generated description by cubic. -->

## Summary by cubic
Added OpenRouter as a first-class option in the setup banner and
introduced a reusable provider card component. This streamlines provider
selection and adds E2E coverage for the setup flow.

- **New Features**
- Added SetupProviderCard and used it for Google and OpenRouter in
SetupBanner.
- Clicking Google or OpenRouter routes to the correct provider settings
and logs PostHog events.
  - Kept “Other providers” link to Settings.
- Added setup.spec.ts E2E test to verify Google, OpenRouter, and Other
navigation; introduced test config flag showSetupScreen to control the
OPENAI_API_KEY shortcut.

<!-- End of auto-generated description by cubic. -->

e2e-tests/helpers/test_helper.ts

@@ -1002,6 +1002,7 @@ export class PageObject {
 
 interface ElectronConfig {
   preLaunchHook?: ({ userDataDir }: { userDataDir: string }) => Promise<void>;
+  showSetupScreen?: boolean;
 }
 
 // From https://github.com/microsoft/playwright/issues/8208#issuecomment-1435475930
@@ -1064,8 +1065,10 @@ export const test = base.extend<{
       process.env.DYAD_ENGINE_URL = "http://localhost:3500/engine/v1";
       process.env.DYAD_GATEWAY_URL = "http://localhost:3500/gateway/v1";
       process.env.E2E_TEST_BUILD = "true";
-      // This is just a hack to avoid the AI setup screen.
-      process.env.OPENAI_API_KEY = "sk-test";
+      if (!electronConfig.showSetupScreen) {
+        // This is just a hack to avoid the AI setup screen.
+        process.env.OPENAI_API_KEY = "sk-test";
+      }
       const baseTmpDir = os.tmpdir();
       const userDataDir = path.join(baseTmpDir, `dyad-e2e-tests-${Date.now()}`);
       if (electronConfig.preLaunchHook) {