perf(map): reuse resources across routes

Preserve standard network layers between map pages while disposing route-owned overlays and controls to prevent memory growth.

src/app/(main)/(map)/hydraulic-simulation/flushing-analysis/page.tsx

@@ -0,0 +1,13 @@
+"use client";
+
+import MapToolbar from "@components/olmap/core/Controls/Toolbar";
+import FlushingAnalysisPanel from "@/components/olmap/FlushingAnalysis/FlushingAnalysisPanel";
+
+export default function Home() {
+  return (
+    <>
+      <MapToolbar queryType="scheme" schemeType="flushing_analysis" />
+      <FlushingAnalysisPanel />
+    </>
+  );
+}