- push digest queries now exclude _duplicate channel like every other
visibility query (bookmarks list/count and NewClassifiedSince)
- advance push watermark to newest scanned story, not pass-start now, so
stories arriving during a long send pass aren't re-counted next pass
- replace hand-rolled escapeHTMLText with stdlib html.EscapeString
- drop em-dashes from user-facing copy; bump PWA CACHE_VERSION so clients
pick up the changed shell assets
35850eaf73