test: playkit v0.3.1 network monitors, authed filters, admin-frontend Vitest

Bump @levkin/playkit to v0.3.1 (network interception helpers) and land the
work it unblocked: startNetworkErrorMonitor on gallery/search/upload/manage-
users, Favorites + People filter UI e2e (storageState), and a fix for the
lingering `res.data: unknown` / Mailpit-vs-Mailtrap type errors in the mail
and catalog specs. Also adds Vitest coverage + a CI job for admin-frontend,
which had no test infra before this.

e2e/package.json

@@ -2,18 +2,16 @@
   "name": "punimtag-e2e",
   "version": "1.0.0",
   "private": true,
-  "description": "PunimTag Playwright e2e \u2014 powered by @levkin/playkit",
+  "description": "PunimTag Playwright e2e — powered by @levkin/playkit",
   "scripts": {
     "test": "playwright test",
-    "test:ui": "playwright test --ui",
-    "test:headed": "playwright test --headed",
     "report": "playwright show-report"
   },
   "engines": {
     "node": ">=20"
   },
   "devDependencies": {
-    "@levkin/playkit": "git+https://git.levkin.ca/ilia/playkit.git#v0.3.0",
+    "@levkin/playkit": "git+https://git.levkin.ca/ilia/playkit.git#v0.3.1",
     "@playwright/test": "^1.52.0",
     "@types/node": "^22.15.0",
     "typescript": "^5.8.0",