#613 - collapse to single-job multi-arch build

Drops the build-client → build-image matrix → merge shape in favor of a
single build-and-push job. ng build still runs once natively on amd64,
then one buildx --platform linux/amd64,linux/arm64 push produces the
multi-arch manifest directly — no per-arch tags, no imagetools merge.

The per-arch work left in Dockerfile.prebuilt is just apk add gettext
and static COPYs, so native runners bought nothing here. All real CPU
work (ng build) already runs native on amd64 outside Docker.

Author: bracyw

.github/workflows/client-build.yml

@@ -8,8 +8,11 @@ env:
   IMAGE_NAME: northeastern-electric-racing/argos-client
 
 jobs:
-  build-client:
+  build-and-push:
     runs-on: ubuntu-24.04
+    permissions:
+      contents: read
+      packages: write
     defaults:
       run:
         working-directory: ./angular-client
@@ -26,31 +29,14 @@ jobs:
       - name: Build production bundle
         run: npm run build:production
 
-      - uses: actions/upload-artifact@v4
-        with:
-          name: client-dist
-          path: angular-client/dist/angular-client/browser
-          if-no-files-found: error
+      # Stage dist where Dockerfile.prebuilt expects it; /dist is in .dockerignore,
+      # so the docker context can't pull from dist/angular-client/browser directly.
+      - name: Stage dist into docker context
+        run: cp -r dist/angular-client/browser browser
 
-  build-image:
-    needs: build-client
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          - { runner: ubuntu-24.04,     platform: linux/amd64, arch: amd64 }
-          - { runner: ubuntu-24.04-arm, platform: linux/arm64, arch: arm64 }
-    runs-on: ${{ matrix.runner }}
-    permissions:
-      contents: read
-      packages: write
-    steps:
-      - uses: actions/checkout@v6
-
-      - uses: actions/download-artifact@v4
+      - uses: docker/setup-qemu-action@v3
         with:
-          name: client-dist
-          path: angular-client/browser
+          platforms: arm64
 
       - uses: docker/setup-buildx-action@v4.0.0
 
@@ -60,33 +46,13 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
-      # No Docker layer cache — apk add gettext is trivial and the dist COPY
-      # invalidates every run. Real build cost (ng build) lives in build-client.
+      # Multi-arch in one buildx push — apk add gettext is the only RUN, fine under QEMU.
+      # All real CPU work (ng build) ran natively above; arch-sensitive part is just the nginx base layer.
       - uses: docker/build-push-action@v7.0.0
         with:
           context: ./angular-client
           file: ./angular-client/Dockerfile.prebuilt
           push: true
-          platforms: ${{ matrix.platform }}
-          tags: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ github.ref_name }}-${{ matrix.arch }}
+          platforms: linux/amd64,linux/arm64
+          tags: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ github.ref_name }}
           provenance: false
-
-  merge:
-    needs: build-image
-    runs-on: ubuntu-24.04
-    permissions:
-      contents: read
-      packages: write
-    steps:
-      - uses: docker/login-action@v4.0.0
-        with:
-          registry: ${{ env.REGISTRY }}
-          username: ${{ github.actor }}
-          password: ${{ secrets.GITHUB_TOKEN }}
-
-      - name: Create multi-arch manifest
-        run: |
-          docker buildx imagetools create \
-            -t ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ github.ref_name }} \
-            ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ github.ref_name }}-amd64 \
-            ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ github.ref_name }}-arm64