chore(ci): bootstrap CI + hooks

Squash-merge bootstrap-cicd into integration

.gitea/workflows/nightly.yml

@@ -0,0 +1,19 @@
+name: Nightly
+
+on:
+  schedule:
+    - cron: '0 3 * * *'
+
+jobs:
+  report:
+    runs-on: docker
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Build CI image
+        run: docker build -f ci.Dockerfile -t local/ci:latest .
+
+      - name: Lint (nightly)
+        run: docker run --rm -v ${{ github.workspace }}:/workspace local/ci:latest bash -lc "cd /workspace && IN_CI_CONTAINER=1 scripts/ci lint"
+