Result presentation: cap per category, "More from …", detail view

Lay out the results inside the popover: cap each category, collapse overflow behind "More from …", and surface external services as an end-of-list button instead of a toggle.

• max 3 results per category
• a category with more shows a "More from …" group header (first row of the group, shown only when it overflows; likely a real button), replacing "Load more results"
• "More from …" opens that category's full results in its own view
• "More/Less from connected services" button at the end of all results (replaces the old toggle), plus a link to the global connected-services setting
• the selected result is visually highlighted (selection behaviour itself is #61655)