add CI

.gitea/workflows/build-stable.yml

@@ -0,0 +1,30 @@
+name: nix docker build stable
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    types: [opened, reopened, synchronize]
+
+jobs:
+  amd64:
+    runs-on: [ nix-flakes, amd64-builder ]
+    steps:
+      - name: System Info
+        run: uname -m
+
+      - name: Setup
+        run: |
+          apt update -y
+          apt install -y curl gnupg
+          curl -fsSL https://deb.nodesource.com/setup_20.x | bash -
+          apt install -y nodejs
+
+      - name: Checkout
+        uses: actions/checkout@v5
+        
+      - name: Build
+        run: |
+          cd stable-with-flakes
+          nix build .#nixos-stable
+