fix: remove duplicate vendor-selector.js include from vendor-themes

The script was being loaded twice - once from base.html and again from
vendor-themes.html, causing "vendorSelectorLog has already been declared".

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

app/templates/admin/vendor-themes.html

@@ -125,6 +125,5 @@
 
 {% block extra_scripts %}
 <script src="https://cdn.jsdelivr.net/npm/tom-select@2.3.1/dist/js/tom-select.complete.min.js"></script>
-<script src="{{ url_for('static', path='shared/js/vendor-selector.js') }}"></script>
 <script src="{{ url_for('static', path='admin/js/vendor-themes.js') }}"></script>
 {% endblock %}