Add workflow to update DefaultMap automatically

.github/workflows/update-default-map.yml

@@ -0,0 +1,57 @@
+name: Update Default Map
+
+on:
+  workflow_dispatch:
+  schedule:
+    - cron: "0 2 * * 0"  # Run every Sunday at 2 AM UTC
+
+jobs:
+  update-map:
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: write
+      pull-requests: write
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Install PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: "8.1"
+          coverage: "none"
+
+      - name: Install Composer dependencies
+        run: composer install --no-progress --ansi
+
+      - name: Update DefaultMap
+        id: update
+        continue-on-error: true
+        run: |
+          php ./bin/fileeye-mimemap update --ansi
+
+      - name: Check for changes
+        id: check
+        run: |
+          if git diff --quiet src/Map/DefaultMap.php; then
+            echo "has_changes=false" >> $GITHUB_OUTPUT
+          else
+            echo "has_changes=true" >> $GITHUB_OUTPUT
+          fi
+
+      - name: Create Pull Request
+        if: steps.check.outputs.has_changes == 'true'
+        uses: peter-evans/create-pull-request@v5
+        with:
+          commit-message: "Update DefaultMap"
+          title: "Update DefaultMap"
+          body: |
+            Automated update of the DefaultMap using the fileeye-mimemap utility.
+
+            This updates the MIME type to file extension mappings from the latest sources.
+          branch: update-default-map-${{ github.run_number }}
+          delete-branch: true