Add automated codebase pie chart update workflow

.github/workflows/update_codebase_chart.yml

@@ -0,0 +1,96 @@
+name: Update Codebase Pie Chart
+
+on:
+  workflow_dispatch:
+  schedule:
+    - cron: '0 4 1 */2 *'  # Run at 4:00 UTC on the 1st day of every 2nd month
+  push:
+    branches:
+      - master
+    paths:
+      - 'scripts/generate_codebase_pie_chart.py'
+      - 'ardupilot_methodic_configurator/**/*.py'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+jobs:
+  update-chart:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write       # for creating branches and commits
+      pull-requests: write  # for creating PRs
+
+    env:
+      CHART_CHANGED: false
+
+    strategy:
+      matrix:
+        python-version: ['3.13']
+
+    steps:
+      - name: Harden the runner (Audit all outbound calls)
+        uses: step-security/harden-runner@ec9f2d5744a09debf3a187a3f4f675c53b671911 # v2.13.0
+        with:
+          egress-policy: audit
+
+      - name: Checkout
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+
+      # https://docs.astral.sh/uv/guides/integration/github/
+      - name: Install uv and set the python version
+        uses: astral-sh/setup-uv@557e51de59eb14aaaba2ed9621916900a91d50c6 # v6.6.1
+        with:
+          python-version: ${{ matrix.python-version }}
+          activate-environment: true
+
+      - name: Install dependencies
+        # required by generate_codebase_pie_chart.py
+        run: |
+            uv pip install .[dev]
+
+      - name: Generate codebase pie chart
+        run: python scripts/generate_codebase_pie_chart.py
+
+      - name: Check for changes and stage them
+        run: |
+          git add images/codebase_structure_pie_chart.png
+          git add images/codebase_structure_pie_chart.svg
+          if [[ -n "$(git status --porcelain)" ]]; then
+            echo "CHART_CHANGED=true" >> $GITHUB_ENV
+          else
+            echo "No changes to commit"
+          fi
+
+      - name: Create Pull Request
+        if: env.CHART_CHANGED == 'true'
+        uses: peter-evans/create-pull-request@271a8d0340265f705b14b6d32b9829c1cb33d45e # v7.0.8
+        with:
+          labels: documentation, automated-pr, codebase-analysis
+          token: ${{ secrets.GITHUB_TOKEN }}
+          branch: update-codebase-chart
+          title: "Update codebase structure pie chart"
+          commit-message: "docs(codebase pie chart): Update codebase structure pie chart with latest metrics"
+          body: |
+            This PR updates the codebase structure pie chart with the latest code metrics.
+
+            The chart shows the distribution of code lines across different categories:
+            - Test Code (Python)
+            - Core Application Code (Python, hand-written)
+            - Generated Code (Python, auto-generated)
+            - Utility Scripts (Python + shell)
+            - Documentation (Markdown files)
+            - Configuration (JSON files)
+
+            Changes were automatically generated by the `scripts/generate_codebase_pie_chart.py` script.
+
+            The updated chart reflects the current state of the codebase and helps track:
+            - Test coverage ratios
+            - Documentation-to-code ratios
+            - Generated vs. hand-written code proportions
+            - Overall project health metrics
+          delete-branch: true