chore: added build workflow

.github/workflows/build.yaml

@@ -0,0 +1,100 @@
+name: Build
+
+on:
+  workflow_dispatch:
+  push:
+    paths-ignore: ["assets/**", "tools/**", "**/*.md", "LICENSE"]
+  pull_request:
+    paths-ignore: ["assets/**", "tools/**", "**/*.md", "LICENSE"]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  prepare:
+    name: Prepare matrix
+    runs-on: ubuntu-latest
+    outputs:
+      envs: ${{ steps.envs.outputs.envs }}
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Python
+        uses: actions/setup-python@v6
+        with:
+          python-version: "3.x"
+
+      - name: Install PlatformIO Core
+        run: |
+          python -m pip install --upgrade pip
+          pip install --upgrade platformio
+          pip install --upgrade intelhex
+
+      - id: envs
+        shell: bash
+        run: |
+          ENVS=$(
+            pio project config --json-output \
+              | jq -c '
+                  .[]
+                  | select(type == "array")
+                  | .[0]
+                  | select(startswith("env:"))
+                  | sub("^env:"; "")
+                ' | jq -s -c '.'
+          )
+
+          echo "envs=$ENVS" >> "$GITHUB_OUTPUT"
+          echo "$ENVS"
+
+  build:
+    name: Build ${{ matrix.env }}
+    runs-on: ubuntu-latest
+    needs: prepare
+
+    strategy:
+      fail-fast: false
+      matrix:
+        env: ${{ fromJson(needs.prepare.outputs.envs) }}
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Python
+        uses: actions/setup-python@v6
+        with:
+          python-version: "3.x"
+
+      - name: Install Node.js
+        uses: actions/setup-node@v5
+        with:
+          node-version: "22"
+
+      - name: Install PlatformIO Core
+        run: |
+          python -m pip install --upgrade pip
+          pip install --upgrade platformio
+          pip install --upgrade intelhex
+
+      - name: Full clean
+        run: |
+          pio run -e ${{ matrix.env }} -t fullclean
+
+      - name: Build firmware & filesystem
+        env:
+          PIOENV: ${{ matrix.env }}
+        run: |
+          pio run -e ${{ matrix.env }}
+
+      - name: Upload artifacts
+        uses: actions/upload-artifact@v7
+        with:
+          name: ${{ matrix.env }}
+          if-no-files-found: error
+          path: |
+            build/*.bin
+            build/*.elf