Side panels: peek a link, feedback, chat, maps, resizable

Reading a story and clicking a link to a source page loses the reader's place. On wide screens open local links in a right-hand pane (an iframe of the local page, so it works offline), with "open as main page"; the same pane holds the feedback panel and the chat, chosen by vertical buttons on the right edge (as on VoiceDebrief); a drag handle sets its width and the width is remembered. A visual clue on each link shows its state (unread, read, noted) from the reader's log.

Done when: on a desk page a local link has a peek control; the pane persists its width; links show state.