story-211: skip selection screen when CLI path argument provided

When a project path is passed on the command line, skip the project
selection screen in the frontend and go straight to the main UI.

Squash merge of feature/story-211

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/tests/e2e/smoke.spec.ts

@@ -1,6 +1,14 @@
 import { expect, test } from "@playwright/test";
 
 test.describe("App boot smoke test", () => {
+	test.beforeEach(async ({ request }) => {
+		// Close any project the server may have auto-opened (e.g. via CLI path
+		// argument) so we always start from the selection screen.
+		await request.delete("/api/project").catch(() => {
+			// Ignore errors when no project is open or backend is unavailable.
+		});
+	});
+
 	test("renders the project selection screen", async ({ page }) => {
 		await page.goto("/");