feat(home): Because you listened recommendation rail (#489)

* feat(home): "Because you listened" recommendation rail

New Home rail (under Recently Added, default on, toggleable in Settings →
Personalisation → Home Page) that surfaces 3 albums from artists similar
to one of your top-played artists. Anchor rotates per Home mount so a
different top-artist seeds the recommendations each visit; within each
anchor, both the similar-artist subset and the chosen album per artist
are randomised, so the same anchor returns different picks on subsequent
visits.

Card layout matches the regular Album cards' surface (--bg-card with
accent-tinted border + 1px inset top highlight) and gets the same
Play / Enqueue hover overlay buttons. Cover and meta scale via CSS only
— no infinite animations, no filter/blur/transform, no compositing
layers. Grid wraps below 3-up at <400px card width instead of shrinking.

API budget: one getArtistInfo2 + 6 parallel getArtist calls per Home
mount, both reusing the existing mostPlayed payload to derive the anchor
pool (no extra API call to find top artists). All 8 locales seeded.

* fix(home): ru plurals + per-server anchor + narrower card grid

- ru: add _few / _many for becauseYouLikeTracks (CLDR Russian needs
  4 forms — 3 треков was wrong, now 3 трека).
- Anchor rotation memory is now per-server. The localStorage key
  becomes psysonic_because_anchor:<serverId>; switching servers no
  longer aliases server A's rotation onto server B's pool.
- because-card grid minmax(400px, 1fr) -> minmax(340px, 1fr) so two
  cards fit side by side at typical sidebar-expanded widths instead
  of collapsing to a single card per row.

* docs: CHANGELOG + Contributors entry for Because-you-listened rail (PR #489)

* style(home): blurred cover backdrop + centred layout for Because-cards

- Each Because-card renders the album cover as a blurred, low-opacity
  full-bleed background layer behind the existing cover thumb and text.
  Resolved through useCachedUrl so the cache layer feeds it (same key
  as the thumbnail) instead of a fresh salted URL on every render.
- Card content (cover thumb + text block) now centred horizontally and
  vertically within the card; the meta line lives in a small pill that
  sits centred under the artist row.
- Text contrast halo and meta-pill background are theme-aware via
  color-mix on var(--bg-card) / var(--text-primary), so the same rules
  read on dark and light themes (was hard-coded rgba black before and
  smudged the type on Latte / Nord Snowstorm).

CHANGELOG.md

@@ -66,6 +66,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * **Composers are a first-class share entity.** `psysonic2-` links with `k=composer` paste to `/composer/:id`; the Share button on the detail page and the right-click menu both copy a `composer` link.
 * Sidebar entry is **off by default** (classical-music use case is a niche) — toggle in Settings → Sidebar.
 
+### Home — "Because you listened" recommendation rail
+
+**By [@Psychotoxical](https://github.com/Psychotoxical), PR [#489](https://github.com/Psychotoxical/psysonic/pull/489)**
+
+* New Home rail that surfaces albums **similar to one of your most-played artists** — Spotify-style "Because you listened to …" recommendations.
+* Anchor artist is rotated **round-robin** between Home opens through the top **8** entries in Most Played (so the rail does not get stuck on the same name). `getArtistInfo` returns up to **12** similar artists; the rail randomly samples **6** of them and surfaces **3** albums (one random per matching artist) that exist on your server.
+* Anchor rotation is **per-server**: switching servers keeps independent rotation state instead of aliasing one server's anchor id onto the next server's pool.
+* Toggleable in the Home customizer like every other rail; respects the existing performance flags ("Disable rail artwork", "Disable Home album rows").
+
 ## Changed
 
 ### Dependencies — npm / Cargo refresh and rodio 0.22