Add loader title hint for SPA navigation feedback

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

app/RSpade/Core/Js/Rsx.js

@@ -491,9 +491,11 @@ class Rsx {
         }
 
         // Collect any extra parameters for query string
+        // Filter out internal parameters that should not appear in URLs
+        const internal_params = ['_loader_title_hint'];
         const query_params = {};
         for (const key in params) {
-            if (!used_params[key]) {
+            if (!used_params[key] && !internal_params.includes(key)) {
                 query_params[key] = params[key];
             }
         }