After the chronological-order fix the page opened on the earliest month
(1995-12), showing only a handful of same-colored dots while the legend
listed every category — looked broken.
- Initialise the plot on the LAST frame (full landscape); Play now replays
the build-up from the start (fromcurrent: false), slider starts at the end.
- Make _extract_month robust: year-only / junk dates (ISO/ETSI 'time' like
'2015/CD Amd 2', bare '2023', '') no longer yield malformed month labels
('2015-/C') or a garbled 'unknown' frame badge.
- Drop undated docs from the temporal animation (they remain on /landscape).
At the full initial frame every category has points, so the legend matches
what is drawn.
Christian Nennemann
e166091388