feat(ui): switch between Cesium and Navara in Visual Presets

Remember the chosen engine and restore the current view after navigation. Keep the standalone JavaScript UI and retire the Dioxus migration and Cesium removal milestones.

scripts/format-scope.json

@@ -1080,6 +1080,7 @@
   "build/navaraAssets.js",
   "scripts/qa-engine-bench.mjs",
   "scripts/qa-engine-shell.mjs",
+  "scripts/qa-engine-switch.mjs",
   "scripts/qa/navara-contract.html",
   "scripts/qa/navaraContractPage.js",
   "scripts/qa/tileCache.mjs",