feat(scenes): rich scene descriptions and control viewer window

Add TipTap editing in the editor and an Electron window on the control panel to read the current scene description.

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

app/shared/ipc/contracts.ts

@@ -81,6 +81,10 @@ export const ipcChannels = {
     togglePresentationFullscreen: 'windows.togglePresentationFullscreen',
     getMultiWindowState: 'windows.getMultiWindowState',
     multiWindowStateChanged: 'windows.multiWindowStateChanged',
+    openSceneDescription: 'windows.openSceneDescription',
+    closeSceneDescription: 'windows.closeSceneDescription',
+    getSceneDescriptionContent: 'windows.getSceneDescriptionContent',
+    sceneDescriptionContent: 'windows.sceneDescriptionContent',
   },
   session: {
     stateChanged: 'session.stateChanged',
@@ -156,6 +160,7 @@ export type IpcEventMap = {
   [ipcChannels.video.stateChanged]: { state: VideoPlaybackState };
   [ipcChannels.license.statusChanged]: { snapshot: LicenseSnapshot };
   [ipcChannels.windows.multiWindowStateChanged]: { open: boolean };
+  [ipcChannels.windows.sceneDescriptionContent]: { html: string };
   [ipcChannels.project.importZipProgress]: ZipProgressEvent;
   [ipcChannels.project.exportZipProgress]: ZipProgressEvent;
   [ipcChannels.project.scenePreviewImportProgress]: ScenePreviewImportEvent;
@@ -373,6 +378,18 @@ export type IpcInvokeMap = {
     req: Record<string, never>;
     res: { open: boolean };
   };
+  [ipcChannels.windows.openSceneDescription]: {
+    req: { html: string };
+    res: { ok: true };
+  };
+  [ipcChannels.windows.closeSceneDescription]: {
+    req: Record<string, never>;
+    res: { ok: true };
+  };
+  [ipcChannels.windows.getSceneDescriptionContent]: {
+    req: Record<string, never>;
+    res: { html: string };
+  };
   [ipcChannels.effects.getState]: {
     req: Record<string, never>;
     res: { state: EffectsState };