update Dockerfile, build nightly

.gitea/workflows/nightly-build.yml

@@ -0,0 +1,20 @@
+name: Nightly Docker Build
+
+on:
+  push:
+  schedule:
+    - cron: '0 0 * * *'  # Midnight
+  workflow_dispatch:     # Allow manual runs
+
+jobs:
+  build-and-push:
+    runs-on: alpine:latest
+    steps:
+      - name: Install dependencies
+        run: apk add docker nodejs
+      - name: Login to Docker registry
+        run: docker login git.arinity.org -u matt -p "${{ secrets.DOCKER_PUSH_TOKEN }}"
+      - name: Checkout repository
+        uses: actions/checkout@v4
+      - name: Build & Push Docker image
+        run: docker build --push --no-cache -t git.arinity.org/meshsense-tools/meshsense:nightly .