Remove the Snow visual preset

Snow is no longer offered anywhere a style can be chosen: the Visual
Presets tray, keyboard shortcut 7, the Cockpit vision carousel, and the
set_visual_style voice action. The shader and its labels go with it;
weather snowfall and the SNOW weather condition are unaffected.

Share links keep working. Snow's enum code (6) stays reserved, so a
compact or long-form link that names it opens on Normal and drops the
Snow shader parameters without reporting them as unknown. A Scene
Director shot saved with Snow plays on Normal too. Snow's frozen share
defaults matched Normal's apart from those parameters, so no other
setting in an old link changes meaning.

The legacy voice-schema pins restore Snow before hashing, so the
unchanged pins still prove nothing else moved; the complete Realtime
payload digest is re-derived.

src/voice/actionSchemas.js

@@ -248,15 +248,7 @@ const schemas = [
       properties: {
         style: {
           type: 'string',
-          enum: [
-            'normal',
-            'retro',
-            'surveillance',
-            'thermal',
-            'anime',
-            'noir',
-            'snow',
-          ],
+          enum: ['normal', 'retro', 'surveillance', 'thermal', 'anime', 'noir'],
         },
       },
       required: ['style'],

src/voice/actionSchemas.test.mjs

@@ -45,7 +45,8 @@ test('the complete Realtime tool payload pins the manifest-generated layer relea
     // S2 GhostMaps extends the generated layer enums.
     // Panel adds named voice targets and timeout; shared Panel/Cockpit guidance
     // is consolidated without changing either feature's arguments.
-    '9ee82c4214499280c208c93751b19d7b724c81b7727a2d0c6dab0184749fbe15',
+    // Snow leaves the set_visual_style enum.
+    '724a82b538a12a994401fc941e175625b032bfb96109934e091d3ef5b9600909',
   );
 });
 
@@ -169,6 +170,18 @@ test('all legacy action arguments are byte-identical after removing the delibera
   // Cyber adds one HUD layout.
   const hud = property('set_hud').layout;
   hud.enum = hud.enum.filter((layout) => layout !== 'cyber');
+  // Snow is retired from set_visual_style; restore it to keep the legacy pin.
+  const visualStyle = legacy.find((tool) => tool.name === 'set_visual_style')
+    .parameters.properties.style;
+  assert.deepEqual(visualStyle.enum, [
+    'normal',
+    'retro',
+    'surveillance',
+    'thermal',
+    'anime',
+    'noir',
+  ]);
+  visualStyle.enum = [...visualStyle.enum, 'snow'];
   // Derived by applying the same removals to the 4b56d0e9 actionSchemas.
   assert.equal(
     createHash('sha256').update(JSON.stringify(legacy)).digest('hex'),

src/voice/gevActions.js

@@ -66,7 +66,6 @@ const ALLOWED_STYLES = new Set([
   'thermal',
   'anime',
   'noir',
-  'snow',
 ]);
 const PANEL_ALIASES = new Map([
   ['data', 'data-panel'],