Add Playwright E2E suite against the built dist/

Pin @playwright/test 1.62.0 (matches the cached chromium
revision) and serve dist/ via python3 http.server, so the
deployed artifact is what gets tested. Covers page load,
terminal commands, vim mode, achievements, and the nav menu.
Ignore node_modules, test-results, playwright-report, and the
phased-execution runtime scratch (.agents/phase-sessions,
pipeline.log).

package.json

@@ -0,0 +1,14 @@
+{
+  "name": "homepage",
+  "version": "1.0.0",
+  "private": true,
+  "description": "Static portfolio site — build (build.sh) + E2E tests (Playwright)",
+  "scripts": {
+    "build": "./build.sh",
+    "test": "playwright test",
+    "test:headed": "playwright test --headed"
+  },
+  "devDependencies": {
+    "@playwright/test": "1.62.0"
+  }
+}