fix(journey): album photos, select-all, heading/hr fixes, dark mode

- Load actual album photos instead of date-range search fallback
  (new GET /albums/:id/photos for Immich + Synology)
- Add select all / deselect all toggle in photo picker
- Normalize Markdown headings to plain text in journal stories
- Fix setext headings (---) rendering as hr instead of h2
- Add remark-breaks for proper line break rendering
- Fix pros/cons dark mode gradient backgrounds
- i18n: selectAll/deselectAll in 14 languages

client/src/i18n/translations/pl.ts

@@ -2014,6 +2014,8 @@ const pl: Record<string, string | { name: string; category: string }[]> = {
   'journey.picker.selected': 'wybranych',
   'journey.picker.addTo': 'Dodaj do',
   'journey.picker.newGallery': 'Nowa galeria',
+  'journey.picker.selectAll': 'Zaznacz wszystko',
+  'journey.picker.deselectAll': 'Odznacz wszystko',
   'journey.picker.noAlbums': 'Nie znaleziono albumów',
   'journey.picker.selectDate': 'Wybierz datę',
   'journey.picker.search': 'Szukaj',