Function read_lsp_messages 

async fn read_lsp_messages(
    stdout: ChildStdout,
    server_id: String,
    event_bus: Arc<EventBus>,
)

Read framed LSP messages from the server’s stdout. Each message is broadcast as an lsp:message event with { server_id, message }. Loop exits on EOF (server died) — the supervisor’s child handle then surfaces the exit via Drop on the next stop cycle.