MCPServerHeaderItem

Server metadata this header row is rendering.

Apply or remove the selected-row styling and re-render the label.

Re-renders content on selection change so dim secondary spans are suppressed on the $primary selection background — the same approach MCPToolItem uses via _desc_style.

Handle click — select the header, or start login on unauth re-click.

Headers are not expandable. Clicking once moves the cursor; clicking the already-selected header for a server in unauthenticated state dismisses the viewer with the server name so the parent app can start in-TUI OAuth login.