feat(scene): video map editor parity and help updates

Enable scene editor, overlays, effects, and darkness on video scenes; brighten GM trap markers; document snap, NPC types, materials, and control controls in RU/EN help.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/main/index.ts

@@ -267,7 +267,9 @@ function emitScenePlayerTokensSessionState(): void {
 function syncSceneDarknessForProject(project: Project): void {
   const cacheKey = project.currentGraphNodeId ?? project.currentSceneId ?? null;
   const scene = project.currentSceneId ? project.scenes[project.currentSceneId] : undefined;
-  const enabled = Boolean(scene?.darkenScene) && scene?.previewAssetType === 'image';
+  const enabled =
+    Boolean(scene?.darkenScene) &&
+    (scene?.previewAssetType === 'image' || scene?.previewAssetType === 'video');
   sceneDarknessStore.switchScene(cacheKey, enabled);
 }