Show a recoverable notice when the globe stops drawing

Cesium stops its render loop after a render error and offers only a
panel that dismisses itself, and a lost WebGL context never draws again,
so the globe froze or went black while the controls kept responding.

The scene chrome now shows an alert dialog with the error. Retry restarts
the render loop and keeps the notice until a frame renders without an
error; after a lost context it reloads the page, whose address keeps the
view. Reset view opens the app root without the restored hash or share
path. An inline conversation panel never reloads its host page. The
application viewer turns off Cesium's own panel; other callers keep it.

scripts/package-boundaries.json

@@ -148,6 +148,7 @@
       "src/ui/kit/UiBadge.vue",
       "src/ui/stores/globeActions.js",
       "src/ui/views/panels/GlobeActions.vue",
+      "src/ui/views/panels/RenderFailure.vue",
       "src/ui/views/panels/GlobeCompass.vue",
       "src/ui/stores/recording.js",
       "src/ui/styleParameters.js",
@@ -2802,6 +2803,7 @@
       "src/ui/displayControls.js",
       "src/ui/effects.js",
       "src/ui/frameRateMonitor.js",
+      "src/ui/renderFailure.js",
       "src/ui/layerPanel.js",
       "src/ui/weatherPanel.js",
       "src/ui/railCards.js",