Open views naming the retired Snow style on Normal

createView threw on style 'snow', so an embed host or a
show_in_gods_eye_view call holding a view from before Snow was retired
was refused outright, camera and layers included. viewFromParams read
style=snow as the recipient's own style, while the app opened the same
link on Normal.

Both now read a retired style as Normal; truly unknown names still
throw. The retired list moves to a browser-free module shared by the
view API, the share codec and visual settings.

src/ui/visualSettings.js

@@ -1,6 +1,7 @@
 import { clampScopeFeatherPct } from '../scopeMaskPolicy.js';
 import { syncScopeControls } from './displayControls.js';
-import { RETIRED_STYLES, STYLE_STATUS_LABELS } from './visualPresets.js';
+import { STYLE_STATUS_LABELS } from './visualPresets.js';
+import { RETIRED_STYLES } from '../visualStylePolicy.js';
 import { syncSegmentedControl } from './segmentedControl.js';
 import { t } from '../i18n/index.js';
 import { UiLifetime } from './uiLifetime.js';