ci(e2e): add Playwright smoke tests to deploy-test workflow

Completes Epic #37 remaining scope:
- playwright.ci.config.ts — targets localhost:3100 (already-running Docker
  app), testMatch restricted to smoke.spec.ts, HTML report on failure
- e2e/smoke.spec.ts — 5 tests: health endpoint, unauth redirect, signin
  page render, admin login redirect, app shell nav visible
- deploy-test.yml — seed admin user via docker exec, setup Node 20, install
  Playwright 1.49 + Chromium, run smoke tests, upload report artifact on failure

Co-Authored-By: claude-flow <ruv@ruv.net>

apps/web/playwright.ci.config.ts

@@ -0,0 +1,25 @@
+import { defineConfig, devices } from "@playwright/test";
+
+export default defineConfig({
+  testDir: "./e2e",
+  testMatch: ["**/smoke.spec.ts"],
+  fullyParallel: false,
+  forbidOnly: true,
+  retries: 1,
+  workers: 1,
+  reporter: process.env["CI"]
+    ? [["list"], ["html", { outputFolder: "playwright-report" }]]
+    : "list",
+  use: {
+    baseURL: "http://localhost:3100",
+    trace: "on-first-retry",
+    screenshot: "only-on-failure",
+  },
+  projects: [
+    {
+      name: "chromium",
+      use: { ...devices["Desktop Chrome"] },
+    },
+  ],
+  // No webServer block — Docker Compose has already started the app
+});