add workflow to run build integrity tests

Author: smdn

.github/dependabot.yml

@@ -0,0 +1,20 @@
+# SPDX-License-Identifier: MIT
+# SPDX-FileCopyrightText: "2025 smdn <smdn@smdn.jp>"
+#
+# ref: https://docs.github.com/code-security/dependabot/working-with-dependabot/dependabot-options-reference
+#
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+      day: "wednesday"
+      time: "03:19"
+      timezone: "Asia/Tokyo"
+    ignore:
+      - dependency-name: "actions/checkout"
+        update-types:
+          ["version-update:semver-minor", "version-update:semver-patch"]
+      - dependency-name: "actions/setup-python"
+        update-types: ["version-update:semver-minor"]

.github/workflows/test-build.yml

@@ -0,0 +1,68 @@
+# SPDX-License-Identifier: MIT
+# SPDX-FileCopyrightText: "2025 smdn <smdn@smdn.jp>"
+
+name: Run build integrity tests
+
+permissions:
+  contents: read
+
+on:
+  push:
+    branches: [ main ]
+    paths:
+      - 'src/**/*.h'
+      - 'src/**/*.hpp'
+      - 'tests/test-build/**/*.cpp'
+
+  pull_request:
+    branches: [ main ]
+    paths:
+      - 'src/**/*.h'
+      - 'src/**/*.hpp'
+      - 'tests/test-build/**/*.cpp'
+
+  workflow_dispatch:
+    inputs:
+      verbose:
+        description: "If true, enables verbose output."
+        required: false
+        type: boolean
+        default: false
+
+jobs:
+  test-build:
+    name: Perform tests of the build integrity
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4.2.2
+      with:
+        token: ${{ secrets.GITHUB_TOKEN }}
+        fetch-depth: 1
+
+    - name: Setup caches
+      uses: actions/cache@v4.2.0
+      with:
+        path: |
+          ~/.cache/pip
+          ~/.platformio/.cache
+        key: ${{ runner.os }}-pio
+
+    - name: Install python
+      uses: actions/setup-python@v5.4.0
+      with:
+        python-version: '3.11'
+
+    - name: Install PlatformIO Core
+      run: |
+        # ref: https://docs.platformio.org/en/stable/integration/ci/github-actions.html#using-cmd-run-command
+        pip install --upgrade platformio
+
+    - name: Build PlatformIO Project
+      shell: pwsh
+      run: |
+        $verbose = '${{ inputs.verbose }}' -ieq 'true'
+
+        pio run