Pages as tabs

[edemaine]

New top nav layout that replaces "page i of n" and next/prev page with a tab for each page:

[Yevhenii, Alice, Joe]

• Move undo/redo to left of zoom buttons (or add separator)
• Page tabs are scrollable if necessary
  • Maybe shorten titles too?
• Pages can have titles (changable by double clicking)
• Icon to show number of people on that page (maxing out at 3 or so)
• Tooltip listing users on a page
• Add page adds at the end
• Re-order pages by dragging
• Button to archive current page
• Button to duplicate current page
• Show archived pages toggle
• Eventual page hierarchy: Chrome-style tab groups that can be minimized, or Vivaldi-style stacked tabs
• List of users available from popup button on right, and can jump to their location. Maybe hovering over them shows their view rectangle (Cursor tracking #5).

Replaces: #135, #102, maybe #18