Delete dead e2e tests for removed panels

Remove tdd-gates, story-todos, and test-protection e2e specs that
tested deleted GatePanel, TodoPanel, and ReviewPanel. Rename the
surviving boot smoke test from review-panel.spec.ts to smoke.spec.ts.

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

frontend/tests/e2e/smoke.spec.ts

@@ -0,0 +1,13 @@
+import { expect, test } from "@playwright/test";
+
+test.describe("App boot smoke test", () => {
+	test("renders the project selection screen", async ({ page }) => {
+		await page.goto("/");
+
+		await expect(page.getByText("StorkIt")).toBeVisible();
+		await expect(page.getByPlaceholder("/path/to/project")).toBeVisible();
+		await expect(
+			page.getByRole("button", { name: "Open Project" }),
+		).toBeVisible();
+	});
+});