fix(artist pin): apply pins in search + fix similar artists (web + android)

Two gaps the pin left, on both platforms:

1. Search still showed the wrong same-name artist's photo. The library search
   now prefers the pin's Deezer picture for a pinned artist (web: search.js
   artist cards; android: LibrarySearchContent via SearchViewModel overrides).

2. Similar Artists were "weird" — they come from Last.fm keyed to the (merged/
   wrong) Navidrome artist. When pinned, use Deezer "related" of the pinned
   artist instead (new deezerRelatedArtists / ItunesClient.lookupRelatedArtists).

Also: web Similar Artists now render with profile pictures (avatar chips), like
the Android app, instead of plain text chips.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

public/sw.js

@@ -1,4 +1,4 @@
-const CACHE = 'ns-v77';
+const CACHE = 'ns-v78';
 const PRECACHE = ['/', 'index.html', 'manifest.json', 'icon.svg'];
 const SKIP_PATHS = ['/rest/stream', '/rest/download', '/config.js'];
 // Auth token params stripped from cache keys so artwork survives across sessions/token refreshes.