Initialize self. See help(type(self)) for accurate signature.

Stable, bookmarkable launcher URL for an app.

This is a front (Angular) route {front}/open/app/{app_key}: it owns the auth-guard (redirecting to login when needed) and the progress UI, and drives the backend gateway APIs (start / handoff). Opening it authenticates the caller, cold-starts the app if needed, shows progress, and navigates into the app (no iframe).

When a one-time code is provided (e.g. issued for a space open), it is carried as ?code= so the front can start the app without an existing lab session.

Open route to access the shared resource, carrying the single-use space access code.

The gws_user_access_token query param name is the legacy wire name (kept for compatibility); it mirrors AuthorizationService.USER_ACCESS_TOKEN_HEADER. Not imported here to keep front_service free of an auth-layer dependency — keep the two in sync.