3.0.0: Redesigned feed, lightbox, weather

• Merged PR #77: Use CSS layers, see https://caniuse.com/css-cascade-layers
  (@thekid)
• Changed current journey to be displayed with a pulsating border in the
  journeys overview map
  (@thekid)
• Fixed weather being incorrect for current dates; there's a 5-day delay
  in the historical data from OpenMeteo
  (@thekid)
• Merged PR #76: Include videos in lightbox using a minimalistic player.
  (@thekid)
• Merged PR #75: If a content is formed of a single video, play in feed
  (@thekid)
• Merged PR #74: Show 1 preview image and collapse the rest into an
  overlapping list in feed
  (@thekid)
• Merged PR #73: Preview previous and next images when swiping inside
  lightbox
  (@thekid)
• Merged PR #72: Show lens model and creation date from EXIF and XMP
  segments. Heads up: This requires to run a migration script, see
  the pull request!
  (@thekid)
• Enabled keyboard navigation with pos1, end and <- and -> arrow
  keys, as well as swiping left and right inside lightbox
  (@thekid)
• Merged PR #71: Aggregate weather for entries when importing. This uses
  the free https://open-meteo.com/en/docs/historical-weather-api API
  (@thekid)
• Merged PR #70: Speed up importing from local directory. The import
  tool was more or less completely rewritten for this purpose. As a side
  effect, it's way more extensible
  (@thekid)
• Fixed issue #69: ffpmeg warnings when converting videos - @thekid
• Implemented support for conditional requests in Atom feed using the
  If-Modified-Since header.
  (@thekid)
• Merged PR #68: Show preview images instead of marker icons on map
  (@thekid)
• Merged PR #67: Switch journeys to display entries oldest - newest
  (@thekid)
• Upgraded Docker image to PHP 8.4 following its release on 2024-11-21
  https://www.php.net/releases/8.4/en.php
  (@thekid)