feat(materials): add campaign materials overlay for sessions

Let GMs manage and show images over the scene from the editor and control panel, with zoom tools, help docs, and full ru/en i18n.

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

app/main/ipc/router.ts

@@ -19,6 +19,7 @@ function channelRequiresLicense(channel: string): boolean {
   if (channel.startsWith('app.')) return false;
   if (channel === ipcChannels.windows.closeMultiWindow) return false;
   if (channel === ipcChannels.windows.closeSceneDescription) return false;
+  if (channel === ipcChannels.windows.closeMaterials) return false;
   if (channel === ipcChannels.windows.togglePresentationFullscreen) return false;
   // Список файлов в %userData%/projects — только чтение; без лицензии список не должен «пропадать».
   if (channel === ipcChannels.project.list) return false;