Each ely://settings/* route used to render its content alone, with no
nav column — so clicking a sidebar item replaced the entire page and
read to users as a brand-new tab opening. Move the nav column into a
shared render_settings_shell wrapper and route every settings/* URL
through it. ely://sync/status reuses the sync route highlight.
Also stop in-place navigation from stealing focus to the omnibar so
the destination page keeps focus for scroll and interaction.