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/app/embed.test.mjs

@@ -146,6 +146,12 @@ test('an embedded page takes views only from its parent and answers it', async (
     id: 3,
     view: { camera: { lat: 1, lon: 2 }, layers: ['flights'] },
   });
+  // A view kept from before Snow was retired still applies, on Normal.
+  send(parent, {
+    type: 'gev:view',
+    id: 4,
+    view: { camera: { lat: 1, lon: 2 }, style: 'snow' },
+  });
   await new Promise((resolve) => setTimeout(resolve, 10));
   assert.deepEqual(posted[1], {
     type: 'gev:view-applied',
@@ -161,6 +167,13 @@ test('an embedded page takes views only from its parent and answers it', async (
         name === 'set_layer_visibility' && args.layerId === 'flights',
     ),
   );
+  assert.equal(posted[3].id, 4);
+  assert.equal(posted[3].ok, true);
+  assert.ok(
+    calls.some(
+      ([name, args]) => name === 'set_visual_style' && args.style === 'normal',
+    ),
+  );
   assert.equal(posted.filter((message) => message.id === 1).length, 0);
   // Ready names no data and goes to any parent; answers go only to the
   // origin that asked.
@@ -168,6 +181,7 @@ test('an embedded page takes views only from its parent and answers it', async (
     '*',
     'https://host.example',
     'https://host.example',
+    'https://host.example',
   ]);
   remove();
 });

src/share/viewCodec.js

@@ -31,9 +31,9 @@ import {
 } from '../data/detectionPolicy.js';
 import { clampScopeFeatherPct } from '../scopeMaskPolicy.js';
 import { VIEW_STYLES } from '../view/index.js';
+import { RETIRED_STYLES } from '../visualStylePolicy.js';
 import {
   GLOBAL_POST_DEFAULTS,
-  RETIRED_STYLES,
   STYLE_PRESET_DEFAULTS,
   STYLES,
 } from '../ui/visualPresets.js';

src/ui/visualPresets.js

@@ -17,12 +17,6 @@ export const STYLES = {
   noir: noirShader,
 };
 
-/**
- * Styles the app no longer offers. A share link, scene or shot that names one
- * opens on Normal instead of keeping whatever style was already showing.
- */
-export const RETIRED_STYLES = Object.freeze(['snow']);
-
 /**
  * The tactical detection look: Dense at 75%.
  *

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';

src/view/index.js

@@ -11,6 +11,7 @@ import {
   decodeLayerStateParams,
   encodeLayerStateParams,
 } from '../data/layerState.js';
+import { RETIRED_STYLES } from '../visualStylePolicy.js';
 
 /** Visual styles by internal name, with the name share links use. */
 export const STYLE_URL_NAMES = Object.freeze({
@@ -253,6 +254,7 @@ export function createView({
 } = {}) {
   if (!Number.isFinite(camera?.lat) || !Number.isFinite(camera?.lon))
     throw new TypeError('A view needs a camera lat and lon');
+  if (RETIRED_STYLES.includes(style)) style = 'normal';
   if (style !== null && !VIEW_STYLES.includes(style))
     throw new TypeError(`Unknown view style: ${style}`);
   if (map !== null && !VIEW_MAPS.includes(map))
@@ -369,9 +371,11 @@ export function viewFromParams(params) {
       pitch_deg: number('pitch'),
     },
     layers: state?.enabledLayerIds ?? [],
-    style: Object.hasOwn(STYLES_BY_URL_NAME, params.get('style'))
-      ? STYLES_BY_URL_NAME[params.get('style')]
-      : null,
+    style: RETIRED_STYLES.includes(params.get('style'))
+      ? 'normal'
+      : Object.hasOwn(STYLES_BY_URL_NAME, params.get('style'))
+        ? STYLES_BY_URL_NAME[params.get('style')]
+        : null,
     map: VIEW_MAPS.includes(map) ? map : null,
     follow,
     annotations: annotationsFromParams(params),

src/view/index.test.mjs

@@ -127,6 +127,14 @@ test('annotations travel in the link, keeping only what the app draws', async ()
   assert.equal(viewToParams(many).has('an'), false);
 });
 
+test('a view naming the retired Snow style opens on Normal', () => {
+  const camera = { lat: 1, lon: 2 };
+  assert.equal(createView({ camera, style: 'snow' }).style, 'normal');
+  const view = viewFromParams(new URLSearchParams('lat=1&lon=2&style=snow'));
+  assert.equal(view.style, 'normal');
+  assert.equal(viewToParams(view).get('style'), 'normal');
+});
+
 test('inherited and unknown style keys do not corrupt a restored view', () => {
   for (const style of [
     'constructor',

src/visualStylePolicy.js

@@ -0,0 +1,7 @@
+/**
+ * Browser-free style vocabulary shared by views, share links and the UI.
+ * Styles the app no longer offers, by the name share links used: a view,
+ * link, scene or shot that names one opens on Normal instead of keeping
+ * whatever style was already showing.
+ */
+export const RETIRED_STYLES = Object.freeze(['snow']);