Expand description
Cocoon → Mountain openExternal notification.
Emitted by Cocoon/.../APIFactoryService.ts:393 when an extension
calls vscode.env.openExternal(uri). Delegates to the platform’s
default handler via the opener crate (already a Mountain dep via
nativeHost:openExternal). Fire-and-forget; success/failure is
logged but not surfaced back to the extension.