fix: ascii quotes in settings.html script tags

The two <script src="{{ url_for(...) }}"> lines for the sync scripts
had Unicode smart-quotes (' / ') instead of ASCII apostrophes —
left over from a copy-paste at some point. Jinja's tokenizer hit the
first one and raised TemplateSyntaxError, so /settings returned a
500. Replaced with ASCII quotes and added the missing ?v=ASSET_VERSION
cache-buster the other static URLs already use.

app/templates/settings.html

@@ -332,8 +332,8 @@
   </div>
 </div>
 
-<script src="{{ url_for(‘static’, path=’/js/portfolio-sync.js’) }}" defer></script>
+<script src="{{ url_for('static', path='/js/portfolio-sync.js') }}?v={{ ASSET_VERSION }}" defer></script>
-<script src="{{ url_for(‘static’, path=’/js/settings-sync.js’) }}" defer></script>
+<script src="{{ url_for('static', path='/js/settings-sync.js') }}?v={{ ASSET_VERSION }}" defer></script>
 {% endif %}
 
 <script>