Merge main and switch Cesium and Navara in place through Vue

Preserve the camera, map source and layer selection across engine sessions. Restore the previous engine if startup fails and retain local history navigation.

scripts/qa-perf.mjs

@@ -323,7 +323,7 @@ try {
     countFrames(2_500),
     page.evaluate(() => new Promise((resolve) => setTimeout(() => {
       // Drive the actual sharpen slider: input event → handler →
-      // _applySharpenIntensity → governorRequestRender. Proves the wiring,
+      // _setSharpenIntensity → governorRequestRender. Proves the wiring,
       // not just the facade.
       const slider = document.getElementById('sharpen-intensity-slider');
       if (!slider) { resolve({ ok: false }); return; }