feat: LIVE/PAUSED toggle controls data fetching on sidebar navigation

LIVE: sidebar clicks trigger initial fetch + polling for the new route.
PAUSED: sidebar clicks navigate but queries are disabled — no fetches
until the user switches back to LIVE.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/api/queries/use-refresh-interval.ts

@@ -8,3 +8,16 @@ export function useRefreshInterval(intervalMs: number): number | false {
   const { autoRefresh } = useGlobalFilters();
   return autoRefresh ? intervalMs : false;
 }
+
+/**
+ * Returns `enabled` and `refetchInterval` tied to the LIVE/PAUSED toggle.
+ * - LIVE: enabled=true, refetchInterval=intervalMs (fetch + poll)
+ * - PAUSED: enabled=false, refetchInterval=false (no fetch at all)
+ */
+export function useLiveQuery(intervalMs: number) {
+  const { autoRefresh } = useGlobalFilters();
+  return {
+    enabled: autoRefresh,
+    refetchInterval: autoRefresh ? intervalMs : false as number | false,
+  };
+}