test(dashboard): add Playwright e2e scaffolding with smoke spec

Milestone A of the frontend test plan. Sets up the test rig — config,
globalSetup that probes the backend and seeds an admin session into
storageState, lightweight fixtures, and a 3-test smoke spec — without
yet covering any user journeys (those land in Milestone B).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

dashboard/playwright.config.ts

@@ -0,0 +1,48 @@
+import { defineConfig, devices } from '@playwright/test';
+import { fileURLToPath } from 'node:url';
+import path from 'node:path';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+
+const DASHBOARD_PORT = Number(process.env.PICLOUD_DASHBOARD_PORT ?? 5173);
+// baseURL is the origin only — the SvelteKit dashboard is mounted at
+// `/admin` (svelte.config.js paths.base), so tests use full paths like
+// `/admin/login` rather than relying on baseURL path resolution.
+const DASHBOARD_BASE = process.env.E2E_BASE_URL ?? `http://localhost:${DASHBOARD_PORT}`;
+
+export default defineConfig({
+	testDir: './tests/e2e',
+	outputDir: './tests/e2e/.results',
+	fullyParallel: true,
+	forbidOnly: !!process.env.CI,
+	retries: process.env.CI ? 1 : 0,
+	workers: process.env.CI ? 2 : undefined,
+	reporter: process.env.CI ? [['html'], ['github']] : 'html',
+	globalSetup: './tests/e2e/global-setup.ts',
+	expect: { timeout: 5_000 },
+	use: {
+		baseURL: DASHBOARD_BASE,
+		actionTimeout: 10_000,
+		navigationTimeout: 15_000,
+		trace: 'on-first-retry',
+		screenshot: 'only-on-failure',
+		video: 'retain-on-failure'
+	},
+	projects: [
+		{
+			name: 'chromium',
+			use: {
+				...devices['Desktop Chrome'],
+				storageState: path.join(__dirname, 'tests/e2e/.auth/admin.json')
+			}
+		}
+	],
+	webServer: {
+		command: 'npm run dev',
+		url: `http://localhost:${DASHBOARD_PORT}/admin/`,
+		reuseExistingServer: !process.env.CI,
+		stdout: 'pipe',
+		stderr: 'pipe',
+		timeout: 60_000
+	}
+});