Added build action

.github/workflows/build-longwaveclock.yml

@@ -0,0 +1,52 @@
+name: "longwave_clock: build for multiple SDK sources"
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - '**'
+jobs:
+  ufbt-build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        include:
+#          - name: Official Dev channel
+#            sdk-channel: dev
+#          - name: Official Release channel
+#            sdk-channel: release
+#          - name: Unleashed Dev
+#            sdk-index-url: https://up.unleashedflip.com/directory.json
+#            sdk-channel: dev
+#          - name: Unleashed Release
+#            sdk-index-url: https://up.unleashedflip.com/directory.json
+#            sdk-channel: release
+          - name: Momentum Dev
+            sdk-index-url: https://up.momentum-fw.dev/firmware/directory.json
+            sdk-channel: dev
+          - name: Momentum Release
+            sdk-index-url: https://up.momentum-fw.dev/firmware/directory.json
+            sdk-channel: release
+    name: 'longwave_clock: ufbt build for ${{ matrix.name }}'
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Build with ufbt
+        uses: flipperdevices/flipperzero-ufbt-action@v0.1.3
+        id: build-app
+        with:
+          sdk-channel: ${{ matrix.sdk-channel }}
+          sdk-index-url: ${{ matrix.sdk-index-url }}
+          app-dir: .
+      - name: Upload app artifacts
+        uses: actions/upload-artifact@v4
+        with:
+          name: longwave_clock-${{ steps.build-app.outputs.suffix }}
+          path: ${{ steps.build-app.outputs.fap-artifacts }}
+      - name: Lint sources
+        uses: flipperdevices/flipperzero-ufbt-action@v0.1.3
+        with:
+          # skip SDK setup, we already did it in previous step
+          skip-setup: true
+          task: lint