feat: add guarded GitHub Pages deployment

pages/deploy.yml

@@ -0,0 +1,34 @@
+name: Deploy GitHub Pages
+
+on:
+  push:
+    branches: [main]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+concurrency:
+  group: pages
+  cancel-in-progress: true
+
+jobs:
+  deploy:
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+      - name: Configure Pages
+        uses: actions/configure-pages@v5
+      - name: Upload site
+        uses: actions/upload-pages-artifact@v4
+        with:
+          path: site
+      - name: Deploy
+        id: deployment
+        uses: actions/deploy-pages@v4

pages/publication-policy.json

@@ -0,0 +1,6 @@
+{
+  "schemaVersion": 1,
+  "repository": "https://github.com/DD4SN/DD4SN.github.io.git",
+  "approvedMasterDataVersion": "fbca8c670e074558b24708bf163fff446a614f709afa9d1784395a15444121b0",
+  "approvedNotBefore": "2026-08-29T15:00:00.000Z"
+}

pages/release-clock.ts

@@ -0,0 +1,25 @@
+export type ReleaseClockSource = 'system';
+
+export type ReleaseClock = {
+  source: ReleaseClockSource;
+  now: () => number;
+};
+
+type ReleaseClockOptions = {
+  wallNow?: () => number;
+};
+
+function systemClock(wallNow: () => number): ReleaseClock {
+  return { source: 'system', now: wallNow };
+}
+
+export function createInitialReleaseClock(
+  _serverNow: unknown,
+  options: ReleaseClockOptions = {}
+): ReleaseClock {
+  return systemClock(options.wallNow ?? Date.now);
+}
+
+export async function synchronizeReleaseClock(options: ReleaseClockOptions = {}): Promise<ReleaseClock> {
+  return systemClock(options.wallNow ?? Date.now);
+}