Auto promote to beta when tests pass (#81)

Use matrix to build, publish to edge, and test on arm64 and amd64. Promote to beta when succeeded.

.github/workflows/snap-ci.yaml

@@ -0,0 +1,92 @@
+name: Snap CI
+
+on:
+  schedule:
+    - cron: "20 2 * * 1" # Monday mornings 02:20 UTC
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+  # Allow manual trigger
+  workflow_dispatch:
+
+env:
+  SNAP_NAME: chip-tool
+
+jobs:
+  build:
+    name: Build, Test, Publish
+    strategy:
+      matrix:
+        runs:
+          - architecture: amd64
+            runner: ubuntu-latest
+          - architecture: arm64
+            runner: [self-hosted, ARM64, Linux]
+    runs-on: ${{ matrix.runs.runner }}
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Build snap
+        uses: snapcore/action-build@v1
+        id: snapcraft
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: ${{env.SNAP_NAME}}_${{github.run_number}}_${{matrix.runs.architecture}}
+          path: ${{ steps.snapcraft.outputs.snap }}
+          if-no-files-found: error
+
+      - name: Publish snap to edge
+        uses: snapcore/action-publish@v1
+        if: github.ref == 'refs/heads/main'
+        env:
+          SNAPCRAFT_STORE_CREDENTIALS: ${{ secrets.STORE_LOGIN }}
+        with:
+          snap: ${{ steps.snapcraft.outputs.snap }}
+          release: latest/edge
+
+      - name: Setup Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: "1.*"
+          cache: false
+
+      - name: Run tests
+        shell: bash
+        working-directory: tests
+        env:
+          TEARDOWN: false
+          SNAP_PATH: ../${{ steps.snapcraft.outputs.snap }}
+        run: |
+          go test -failfast -p 1 -timeout 30m -v
+
+      - name: Upload snap logs
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: logs_${{ github.run_number}}_${{matrix.runs.architecture}}
+          path: tests/logs/*.log
+
+  promote-beta:
+    name: Promote to Beta
+    # Only promote if we are on the main branch
+    if: github.ref == 'refs/heads/main'
+    runs-on: ubuntu-latest
+    needs: [build]
+    steps:
+      - name: Install Snapcraft
+        run: |
+          sudo snap install snapcraft --classic
+          echo /snap/bin >> $GITHUB_PATH
+        shell: bash
+
+      - name: Promote Snap
+        env: # Workaround for https://github.com/snapcore/snapcraft/issues/4439
+          SNAPCRAFT_HAS_TTY: "true"
+          SNAPCRAFT_STORE_CREDENTIALS: ${{ secrets.STORE_LOGIN }}
+        run: |
+          yes | snapcraft promote $SNAP_NAME --from-channel latest/edge --to-channel latest/beta