Embedding Explorer: share neighbor views, clear URL after load, clean up console logs

- Share button captures selected neighbor + camera for neighbor view URLs
- Share URL params cleared after load (history.replaceState) so refresh is clean
- Removed console.log debug output from camera polling script

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app.py

@@ -971,6 +971,19 @@ if(!location.search.includes("__theme=light")){
     }, 500);
 })();
 </script>
+<script>
+// Clear share params from URL after load (so refresh doesn't re-apply)
+if (new URL(location).searchParams.has('q')) {
+    var _clearId = setInterval(function() {
+        if (document.querySelector('.js-plotly-plot')) {
+            var clean = new URL(location.pathname, location.origin);
+            clean.searchParams.set('__theme', 'light');
+            history.replaceState(null, '', clean.toString());
+            clearInterval(_clearId);
+        }
+    }, 500);
+}
+</script>
 """
 
 _LIGHT = {