Add tests for Dialog and Tooltip, raise components/ui threshold to 93%

Dialog: open/close lifecycle, cancel event handling, DialogHeader.
Tooltip: show on pointer enter, hide on pointer leave. Raises
components/ui coverage threshold to enforce testing of future
primitives.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/web/src/components/__tests__/dialog.test.tsx

@@ -0,0 +1,71 @@
+// @vitest-environment jsdom
+import { cleanup, render, screen } from "@testing-library/react";
+import { userEvent } from "@testing-library/user-event";
+import { afterEach, beforeAll, describe, expect, it, vi } from "vitest";
+import { Dialog, DialogHeader } from "../ui/dialog.js";
+
+beforeAll(() => {
+	HTMLDialogElement.prototype.showModal =
+		HTMLDialogElement.prototype.showModal ||
+		function showModal(this: HTMLDialogElement) {
+			this.setAttribute("open", "");
+		};
+	HTMLDialogElement.prototype.close =
+		HTMLDialogElement.prototype.close ||
+		function close(this: HTMLDialogElement) {
+			this.removeAttribute("open");
+		};
+});
+
+afterEach(cleanup);
+
+describe("Dialog", () => {
+	it("opens when open=true", () => {
+		render(
+			<Dialog open={true} onClose={() => {}}>
+				Content
+			</Dialog>,
+		);
+		expect(screen.getByText("Content")).toBeDefined();
+	});
+
+	it("closes when open changes from true to false", () => {
+		const { rerender } = render(
+			<Dialog open={true} onClose={() => {}}>
+				Content
+			</Dialog>,
+		);
+		const dialog = document.querySelector("dialog");
+		expect(dialog?.hasAttribute("open")).toBe(true);
+
+		rerender(
+			<Dialog open={false} onClose={() => {}}>
+				Content
+			</Dialog>,
+		);
+		expect(dialog?.hasAttribute("open")).toBe(false);
+	});
+
+	it("calls onClose on cancel event", () => {
+		const onClose = vi.fn();
+		render(
+			<Dialog open={true} onClose={onClose}>
+				Content
+			</Dialog>,
+		);
+		const dialog = document.querySelector("dialog");
+		dialog?.dispatchEvent(new Event("cancel"));
+		expect(onClose).toHaveBeenCalledOnce();
+	});
+});
+
+describe("DialogHeader", () => {
+	it("renders title and close button", async () => {
+		const onClose = vi.fn();
+		render(<DialogHeader title="Test Title" onClose={onClose} />);
+
+		expect(screen.getByText("Test Title")).toBeDefined();
+		await userEvent.click(screen.getByRole("button"));
+		expect(onClose).toHaveBeenCalledOnce();
+	});
+});