Fix nav spot tickers: register JS in static allowlist and harden price fetch.

Co-authored-by: Cursor <cursoragent@cursor.com>

lib/instance/templates/embed_shell.html

@@ -149,7 +149,7 @@ const ORDER_ENTRY_MODEL_CODE_TO_CATEGORY = {{ entry_model_code_to_category | toj
 <script src="/static/instance_stats.js?v=5"></script>
 {% include 'embed_boot_scripts.html' %}
 <script src="/static/options_expiry_countdown.js?v=1"></script>
-<script src="/static/nav_spot_tickers.js?v=1"></script>
+<script src="/static/nav_spot_tickers.js?v=2"></script>
 <script src="/static/instance_dashboard.js?v=5"></script>
 <script src="/static/account_ledger.js?v=1"></script>
 <script>