Add wc-licensed-product-client as git submodule

- Bundle magdev/wc-licensed-product-client as git submodule
- Update composer.json to use path repository instead of VCS
- Update .gitignore to allow submodule in vendor directory
- Update CI workflow to checkout submodules recursively
- Remove private repository authentication step (no longer needed)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.gitea/workflows/release.yml

@@ -11,6 +11,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
+        with:
+          submodules: recursive
 
       - name: Setup PHP
         uses: shivammathur/setup-php@v2
@@ -29,12 +31,6 @@ jobs:
       - name: Validate composer.json
         run: composer validate --strict
 
-      - name: Configure Composer for private repository
-        env:
-          GITEA_TOKEN: ${{ secrets.SRC_GITEA_TOKEN }}
-        run: |
-          composer config --global http-basic.src.bundespruefstelle.ch token "${GITEA_TOKEN}"
-
       - name: Install Composer dependencies (production)
         run: |
           composer config platform.php 8.3.0
@@ -92,6 +88,7 @@ jobs:
             -x "${PLUGIN_NAME}/*.log" \
             -x "${PLUGIN_NAME}/logs/*" \
             -x "${PLUGIN_NAME}/.gitignore" \
+            -x "${PLUGIN_NAME}/.gitmodules" \
             -x "${PLUGIN_NAME}/.editorconfig" \
             -x "${PLUGIN_NAME}/phpcs.xml*" \
             -x "${PLUGIN_NAME}/phpunit.xml*" \