The version strings are dates ("2026.11.01"), so a release has no
identity that is not a date. Every entry now also carries a release
number and the short SHA of the commit it went out with.
The date-shaped version string is left in place for now — the popup
switches over and drops it in the next commit, so this one stays
green on its own.
A test holds the numbering unique, contiguous and newest-first, and
holds every commit to a real SHA.
The sidebar's bottom block gets two new controls:
- A "What's New" button that opens the release-note popup, with a badge
until the operator has read the latest release.
- A Dark Mode section that replaces the old one-click toggle with an
explicit Light/Dark switch, so the current mode is always visible
instead of being inferred from the button's label.
The theme colour picker stays in Settings -> Appearance; the sidebar
carries the mode switch only, so the nav rail is not a strip of 16
coloured squares.
