GET /api/video/downloads/history (paged, ?kind/search/outcome) + /history/<id>, both
returning the live tab counts. New self-contained modal (video-download-history.js,
.vdh-* styles) opened from a History button on the Downloads page: day-grouped
timeline of every grab with poster, title, S/E, quality/resolution/codec/size and an
outcome badge; rows expand in place to reveal the full detail (release, source/uploader,
codecs, dest path, grabbed/finished times, error). Tabs (All/Movies/TV), search,
load-more, and a live count badge on the button.
