D18. Desktop app: Electron, one engine, React (6 Oct 2026)

Electron rather than Tauri: the canvas must render slides with the engine that elabora fit, captures and tests measure (Chromium; Tauri uses WebKit on macOS), the core runs on Node, and Electron’s Node runs the elabora command for testers who have no Node. One engine process holds the project in memory and is the only writer while the app is open; the CLI and MCP keep working on the same folder. The UI is React with fine-grained subscriptions; the canvas is the player in an iframe. Milestone 1 has no accounts, no hosting and no provided AI: « Demander à l’IA » opens Claude Desktop (claude://cowork/new or claude://code/new with the folder) or the Codex app (codex://threads/new with the path), or copies the request. Revisit if: the app’s memory footprint becomes a problem on testers’ machines.