ci: unify workflows - split build per component, single tag-triggered pipeline

.gitea/workflows/build_device_agent.yaml

@@ -0,0 +1,43 @@
+name: Build Device Agent
+
+on:
+  workflow_call:
+
+jobs:
+  cross-build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        goos: [linux, windows]
+        goarch: [amd64, arm64]
+        exclude:
+          - goos: windows
+            goarch: arm64
+    defaults:
+      run:
+        working-directory: apps/device-agent
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: true
+          fetch-depth: 0
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version: '1.26'
+
+      - name: Build
+        env:
+          CGO_ENABLED: '0'
+          GOOS: ${{ matrix.goos }}
+          GOARCH: ${{ matrix.goarch }}
+        run: |
+          EXT=""
+          if [ "${{ matrix.goos }}" = "windows" ]; then EXT=".exe"; fi
+          go build -o bin/nexus-device-agent-${{ matrix.goos }}-${{ matrix.goarch }}${EXT} .
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: nexus-device-agent-${{ matrix.goos }}-${{ matrix.goarch }}
+          path: apps/device-agent/bin/nexus-device-agent-*