fix: refresh request list when tab becomes visible

Browser throttles SSE in background tabs, causing missed updates.
Use Page Visibility API to reload requests when user returns to tab.

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

Author: vigo

internal/webui/static/index.html

@@ -1013,6 +1013,13 @@ <h3>Body</h3>
             initialLoadDone = true;
             connectSSE();
         });
+
+        // Refresh when tab becomes visible (catches requests missed while in background)
+        document.addEventListener('visibilitychange', () => {
+            if (document.visibilityState === 'visible') {
+                loadInitialRequests();
+            }
+        });
     </script>
 </body>
 </html>