ci(github): add PR Verify workflow — required check for main protection

Mirrors .gitlab-ci.yml's verify stage (typecheck/lint/translations/build)
on GitHub Actions, since GitHub is being reactivated as a working build
path while gitlab.vnc.biz's own registry and runner are blocked (see
docs memory: gitlab-registry-dependency-proxy). Runs on PRs into main or
dev; wired as main's required status check.

.github/workflows/pr-verify.yml

@@ -0,0 +1,28 @@
+name: PR Verify
+
+# Required status check on `main` (Settings -> Branches). Mirrors the GitLab
+# CI `verify` stage (.gitlab-ci.yml) so both remotes gate merges the same
+# way: typecheck, lint, translations, and a real production build — no
+# registry, no cluster, nothing that can be blocked by infra that's down.
+on:
+  pull_request:
+    branches:
+      - main
+      - dev
+
+jobs:
+  verify:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 24
+          cache: npm
+      - run: npm ci
+      - run: npm run typecheck
+      - run: npm run lint
+      - run: npm run test:translations
+      - run: npm run build
+        env:
+          GIT_COMMIT: ${{ github.sha }}