ci: add build workflow for fork

.github/workflows/build-fork.yml

@@ -0,0 +1,42 @@
+name: Build Fork
+
+on:
+  push:
+    branches:
+      - feat/bandwidth-limiting
+  workflow_dispatch:
+
+jobs:
+  docker-build:
+    name: Build & Push Docker Image
+    runs-on: ubuntu-latest
+    permissions:
+      packages: write
+      contents: read
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Build and push
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          platforms: linux/amd64
+          push: true
+          tags: |
+            ghcr.io/${{ github.repository }}:latest
+            ghcr.io/${{ github.repository }}:${{ github.sha }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=min