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/ui/cyberTheme.test.mjs

@@ -105,7 +105,6 @@ test('visual styles retain Cyber through real preset application without droppin
     'normal',
     'noir',
     'anime',
-    'snow',
     'thermal',
     'retro',
   ]) {
@@ -162,8 +161,8 @@ test('a preset explicitly selected in Cyber survives exit and resets for re-entr
   owner.setStyle('noir');
 
   owner._setHudVariant('cyber', { applyVisualDefaults: true });
-  owner.setStyle('snow', { userInitiated: true });
-  assert.equal(owner.activeStyle, 'snow');
+  owner.setStyle('anime', { userInitiated: true });
+  assert.equal(owner.activeStyle, 'anime');
   assert.equal(owner._preCyberStyle, 'noir');
   assert.equal(owner._cyberStyleUserSelected, true);
 
@@ -172,16 +171,16 @@ test('a preset explicitly selected in Cyber survives exit and resets for re-entr
   assert.equal(owner._preCyberStyle, 'noir');
   owner._setHudVariant('operator', { applyVisualDefaults: true });
   assert.equal(hud.getVariant(), 'operator');
-  assert.equal(owner.activeStyle, 'snow');
+  assert.equal(owner.activeStyle, 'anime');
   assert.equal(owner._preCyberStyle, null);
   assert.equal(owner._cyberStyleUserSelected, false);
 
   // A later untouched Cyber round trip restores the new pre-Cyber preset.
   owner._setHudVariant('cyber', { applyVisualDefaults: true });
   assert.equal(owner.activeStyle, 'thermal');
-  assert.equal(owner._preCyberStyle, 'snow');
+  assert.equal(owner._preCyberStyle, 'anime');
   owner._setHudVariant('minimal', { applyVisualDefaults: true });
-  assert.equal(owner.activeStyle, 'snow');
+  assert.equal(owner.activeStyle, 'anime');
 });
 
 test('an explicit same-value FLIR choice is preserved on Cyber exit', (t) => {
@@ -200,15 +199,15 @@ test('an authoritative same-Cyber reset clears local preset ownership', (t) => {
   const { owner } = styleOwner(t, 'tactical');
   owner.setStyle('noir');
   owner._setHudVariant('cyber', { applyVisualDefaults: true });
-  owner.setStyle('snow', { userInitiated: true });
+  owner.setStyle('anime', { userInitiated: true });
   assert.equal(owner._cyberStyleUserSelected, true);
 
   owner._setHudVariant('cyber');
-  assert.equal(owner.activeStyle, 'snow');
+  assert.equal(owner.activeStyle, 'anime');
   assert.equal(owner._preCyberStyle, null);
   assert.equal(owner._cyberStyleUserSelected, false);
   owner._setHudVariant('operator', { applyVisualDefaults: true });
-  assert.equal(owner.activeStyle, 'snow');
+  assert.equal(owner.activeStyle, 'anime');
 });
 
 test('Display and voice HUD routes preserve explicit Cyber entry and exit authority', async (t) => {
@@ -226,10 +225,10 @@ test('Display and voice HUD routes preserve explicit Cyber entry and exit author
   const display = makeOwner();
   const hudLayout = new EventTarget();
   hudLayout.value = 'cyber';
-  const snowButton = new EventTarget();
-  snowButton.dataset = { style: 'snow' };
+  const animeButton = new EventTarget();
+  animeButton.dataset = { style: 'anime' };
   const controls = bindDisplayControls({
-    elements: { hudLayout, styleButtons: [snowButton] },
+    elements: { hudLayout, styleButtons: [animeButton] },
     actions: {
       setHudLayout: (value) => display.owner.setHudLayout(value),
       setStyle: (value) =>
@@ -239,12 +238,12 @@ test('Display and voice HUD routes preserve explicit Cyber entry and exit author
   hudLayout.dispatchEvent(new Event('change'));
   assert.equal(display.hud.getVariant(), 'cyber');
   assert.equal(display.owner.activeStyle, 'thermal');
-  snowButton.dispatchEvent(new Event('click'));
-  assert.equal(display.owner.activeStyle, 'snow');
+  animeButton.dispatchEvent(new Event('click'));
+  assert.equal(display.owner.activeStyle, 'anime');
   hudLayout.value = 'operator';
   hudLayout.dispatchEvent(new Event('change'));
   assert.equal(display.hud.getVariant(), 'operator');
-  assert.equal(display.owner.activeStyle, 'snow');
+  assert.equal(display.owner.activeStyle, 'anime');
   controls.destroy();
 
   const voice = makeOwner();
@@ -263,13 +262,13 @@ test('Display and voice HUD routes preserve explicit Cyber entry and exit author
   assert.equal(entered.ok, true);
   assert.equal(voice.hud.getVariant(), 'cyber');
   assert.equal(voice.owner.activeStyle, 'thermal');
-  const selected = await runVoiceAction('set_visual_style', { style: 'snow' });
+  const selected = await runVoiceAction('set_visual_style', { style: 'anime' });
   assert.equal(selected.ok, true);
-  assert.equal(voice.owner.activeStyle, 'snow');
+  assert.equal(voice.owner.activeStyle, 'anime');
   const exited = await runVoiceAction('set_hud', { layout: 'operator' });
   assert.equal(exited.ok, true);
   assert.equal(voice.hud.getVariant(), 'operator');
-  assert.equal(voice.owner.activeStyle, 'snow');
+  assert.equal(voice.owner.activeStyle, 'anime');
 });
 
 test('scope choice and expanded feather survive every HUD layout and both restore paths', async (t) => {
@@ -301,11 +300,18 @@ test('scope choice and expanded feather survive every HUD layout and both restor
   assert.equal(owner._scopeFeatherSlider.value, '200');
 });
 
+test('a scene shot saved with the retired Snow style plays on Normal', async (t) => {
+  const { owner } = styleOwner(t, 'tactical');
+  owner.setStyle('noir');
+  await owner.applyVisualState({ style: 'snow' });
+  assert.equal(owner.activeStyle, 'normal');
+});
+
 test('scene and share HUD transitions do not restore a local pre-Cyber preset', async (t) => {
   const { owner, hud } = styleOwner(t, 'tactical');
   owner.setStyle('noir');
   owner._setHudVariant('cyber', { applyVisualDefaults: true });
-  owner.setStyle('snow', { userInitiated: true });
+  owner.setStyle('anime', { userInitiated: true });
   assert.equal(owner._cyberStyleUserSelected, true);
 
   await owner.applyVisualState({ style: 'retro', hud: { variant: 'cyber' } });
@@ -319,7 +325,7 @@ test('scene and share HUD transitions do not restore a local pre-Cyber preset',
   owner.setStyle('surveillance');
   owner._setHudVariant('cyber', { applyVisualDefaults: true });
   assert.equal(owner._preCyberStyle, 'surveillance');
-  owner.setStyle('snow', { userInitiated: true });
+  owner.setStyle('anime', { userInitiated: true });
   await owner.restoreShareState({
     style: 'thermal',
     hudVariant: 'cyber',