async fn handle_pane_open(
__arg0: State<AppState>,
__arg1: Json<CommandPaneOpenData>,
) -> impl IntoResponseExpand description
POST /api/v1/pane/open — open a pane (editor/term/browser/…).
Called by agentmux-mcp’s OpenEditor tool. Thin HTTP wrapper over
app_api::open_pane (the same logic the WebSocket pane.open RPC uses):
creates the block, enqueues the layout action, and broadcasts the updates
so the frontend renders the pane. Body is CommandPaneOpenData.