A plain click on a page cleared the text selection whatever modifiers were
held, so there was no way to extend a selection with Shift+click as in
Acrobat. Now, when Shift is held and there is a text selection on the
clicked page, the click moves the selection head to the nearest text
position and keeps the anchor. Without Shift, or with no selection on that
page, a click still clears the selection. Selections remain single-page:
cross-page selection (the issue's second request) is not part of this
change.
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
