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-lock.json

@@ -8,7 +8,7 @@
       "name": "punimtag-e2e",
       "version": "1.0.0",
       "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",
@@ -19,8 +19,8 @@
       }
     },
     "node_modules/@levkin/playkit": {
-      "version": "0.3.0",
-      "resolved": "git+https://git.levkin.ca/ilia/playkit.git#7369b1c5e53e1f7511bea96be9042e663b60b315",
+      "version": "0.3.1",
+      "resolved": "git+https://git.levkin.ca/ilia/playkit.git#3380ba95115423950b4ba0855cc9367475d7f7cf",
       "dev": true,
       "license": "MIT",
       "dependencies": {