v0.27.0

• A new review interface. Sorting is now a table: every waiting face at once, grouped
  into cards by the person FaceID thinks it is (Suggested above the suggest threshold,
  Maybe below it, No match yet). Pick faces and drop them on a person — tap a pile, press
  1–9, drag with the mouse, or search everyone with P. Every face has a ⛶ button for the
  full snapshot, and the snapshot itself lets you assign straight away. Assigning, ignoring
  and applying suggestions can be undone; discarding crops and deleting photos commit only
  after the undo toast is gone.
• People, history, log, tools and settings in the same design, with nothing left out:
  upload photos, rename, favourites, set-aside photos with their reason, the ignore list,
  was wrong analysis, measurements, backup and restore. Settings are split into four
  sections and keep unsaved changes in one bar instead of saving field by field.
• One Checks page for all measurements, always in the header: the recognition test
  (formerly Settings → Does it actually work?) first, then speed, coverage and why events
  yield no face (formerly the opt-in Tools tab). Settings now hold only settings.
• Key image per person. POST /api/persons/{slug}/cover with {"file": …} (or
  null) picks the photo that represents a person everywhere in the interface; it is
  stored in meta.json and travels with backups. Matching is unaffected. If that photo is
  set aside or deleted, the newest photo takes its place.
• Undo also works for people at the photo limit. There a new face can be set aside at
  once, or push an older photo out. Undo now sends set-aside new faces straight back to
  sorting (POST /api/persons/{slug}/trimmed/{file}/unassign) and restores the photos they
  pushed out, instead of only removing the faces that stayed.
• Photos sent back to sorting keep their camera and time. Unassigning used to blank both;
  set-aside photos now remember where they came from, and restoring one puts that back too.
• Light and dark, following the system, switchable in the header. Colours follow the
  FaceID logo; fonts (Unbounded, Albert Sans — SIL OFL) ship in static/assets, so the
  interface loads nothing from outside.
• The previous interface stays at /classic for this release, as a way back if
  something you rely on is missing. Settings and the shortcuts sheet link to it, and it links
  back; both links are relative, so they work behind Home Assistant ingress.