feat: add pre-commit workflow for code quality automation (#140)

Add comprehensive pre-commit GitHub Actions workflow including:
- Terraform formatting and validation
- Documentation generation with terraform-docs
- TFLint analysis for best practices
- File formatting and consistency checks
- Optimized caching and parallel execution

Author: lgallard

.github/workflows/pre-commit.yml

@@ -0,0 +1,138 @@
+name: Pre-commit
+
+on:
+  pull_request:
+    branches: [master]
+    paths:
+      - '**.tf'
+      - '**.tfvars'
+      - '**.md'
+      - '.pre-commit-config.yaml'
+  push:
+    branches: [master]
+    paths:
+      - '**.tf'
+      - '**.tfvars'
+      - '**.md'
+      - '.pre-commit-config.yaml'
+
+jobs:
+  pre-commit:
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    permissions:
+      contents: read
+      pull-requests: read
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.11'
+
+      - name: Set up Terraform
+        uses: hashicorp/setup-terraform@v3
+        with:
+          terraform_version: '1.3.0'
+
+      - name: Cache terraform tools
+        uses: actions/cache@v3
+        with:
+          path: |
+            ~/.local/bin/terraform-docs
+            ~/.local/bin/tflint
+          key: terraform-tools-${{ runner.os }}-v1
+          restore-keys: |
+            terraform-tools-${{ runner.os }}-
+
+      - name: Install terraform-docs
+        run: |
+          if [ ! -f ~/.local/bin/terraform-docs ]; then
+            echo "Installing terraform-docs..."
+            mkdir -p ~/.local/bin
+            curl -sSLo ./terraform-docs.tar.gz https://terraform-docs.io/dl/v0.16.0/terraform-docs-v0.16.0-$(uname)-amd64.tar.gz
+            tar -xzf terraform-docs.tar.gz
+            chmod +x terraform-docs
+            mv terraform-docs ~/.local/bin/
+            rm terraform-docs.tar.gz
+          fi
+          echo "$HOME/.local/bin" >> $GITHUB_PATH
+
+      - name: Install tflint
+        run: |
+          if ! command -v tflint &> /dev/null; then
+            echo "Installing tflint..."
+            curl -s https://raw.githubusercontent.com/terraform-linters/tflint/master/install_linux.sh | bash
+          fi
+
+      - name: Install pre-commit
+        run: |
+          python -m pip install --upgrade pip
+          pip install pre-commit
+
+      - name: Cache pre-commit hooks
+        uses: actions/cache@v3
+        with:
+          path: ~/.cache/pre-commit
+          key: pre-commit-${{ runner.os }}-${{ hashFiles('.pre-commit-config.yaml') }}
+          restore-keys: |
+            pre-commit-${{ runner.os }}-
+
+      - name: Install pre-commit hooks
+        run: pre-commit install-hooks
+
+      - name: Run pre-commit on all files (push to master)
+        if: github.event_name == 'push' && github.ref == 'refs/heads/master'
+        run: pre-commit run --all-files
+
+      - name: Run pre-commit on changed files (pull request)
+        if: github.event_name == 'pull_request'
+        run: |
+          # Get the list of changed files
+          git fetch origin ${{ github.base_ref }}
+          CHANGED_FILES=$(git diff --name-only origin/${{ github.base_ref }}...HEAD -- '*.tf' '*.tfvars' '*.md')
+
+          if [ -n "$CHANGED_FILES" ]; then
+            echo "Running pre-commit on changed files:"
+            echo "$CHANGED_FILES"
+            pre-commit run --files $CHANGED_FILES
+          else
+            echo "No relevant files changed, skipping pre-commit checks"
+          fi
+
+      - name: Pre-commit summary
+        if: always()
+        run: |
+          echo "## 🔍 Pre-commit Results" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+
+          if [ "${{ job.status }}" == "success" ]; then
+            echo "✅ All pre-commit checks passed!" >> $GITHUB_STEP_SUMMARY
+            echo "" >> $GITHUB_STEP_SUMMARY
+            echo "**Tools verified:**" >> $GITHUB_STEP_SUMMARY
+            echo "- 🔧 Terraform formatting" >> $GITHUB_STEP_SUMMARY
+            echo "- ✅ Terraform validation" >> $GITHUB_STEP_SUMMARY
+            echo "- 📚 Documentation generation" >> $GITHUB_STEP_SUMMARY
+            echo "- 🔍 TFLint analysis" >> $GITHUB_STEP_SUMMARY
+            echo "- 🧹 File formatting" >> $GITHUB_STEP_SUMMARY
+          else
+            echo "❌ Pre-commit checks failed" >> $GITHUB_STEP_SUMMARY
+            echo "" >> $GITHUB_STEP_SUMMARY
+            echo "Please check the logs above for specific failures." >> $GITHUB_STEP_SUMMARY
+            echo "You can run \`pre-commit run --all-files\` locally to fix issues." >> $GITHUB_STEP_SUMMARY
+          fi
+
+          echo "" >> $GITHUB_STEP_SUMMARY
+          echo "**Configured hooks:**" >> $GITHUB_STEP_SUMMARY
+          echo "- trailing-whitespace" >> $GITHUB_STEP_SUMMARY
+          echo "- end-of-file-fixer" >> $GITHUB_STEP_SUMMARY
+          echo "- check-yaml" >> $GITHUB_STEP_SUMMARY
+          echo "- terraform_fmt" >> $GITHUB_STEP_SUMMARY
+          echo "- terraform_validate" >> $GITHUB_STEP_SUMMARY
+          echo "- terraform_docs" >> $GITHUB_STEP_SUMMARY
+          echo "- terraform_tflint" >> $GITHUB_STEP_SUMMARY