feat(queue): add Now-Playing Info tab with artist bio, song credits and Bandsintown tour dates (#244)

* feat(queue): add Now-Playing Info tab with artist bio, song credits and Bandsintown tour dates

A third tab in the right-side queue panel surfaces context for the
currently playing track:

- Artist card: image + biography from Subsonic getArtistInfo (Last.fm
  "Read more on Last.fm" anchor stripped), with read-more toggle that
  only appears when the bio actually overflows the 4-line clamp.
- Song info: contributor credits from OpenSubsonic contributors[]
  rendered stacked (name prominent, role muted). Section is hidden
  entirely on servers without contributor support, and rows that just
  re-state the main artist under role "artist" are filtered out.
- On tour: optional Bandsintown integration (opt-in, off by default).
  HTTP fetch + JSON parsing happen entirely on the Rust side; the
  frontend wrapper deduplicates concurrent calls and caches results in
  RAM for the session. Limited to 5 events with a "Show N more" toggle.
  When the toggle is off, the section becomes an in-place opt-in card
  with a privacy info-tooltip explaining what data is sent — same
  tooltip is also exposed on the matching toggle in Settings.

Caching: artist info and song detail are memoised by stable IDs across
component remounts, so jumping between tracks of the same album/artist
does not refire the network calls.

Implementation notes:
- Bandsintown app_id "js_app_id" — arbitrary strings (e.g. "psysonic")
  now return HTTP 403 from rest.bandsintown.com; js_app_id is the ID
  Bandsintown's own embeddable widget uses and is broadly accepted.
- Tour items use negative left/right margins so the date badge stays
  visually aligned with the section title while the hover background
  extends slightly past the section edges.
- New i18n namespace nowPlayingInfo across all 8 locales (en, de, fr,
  nl, zh, nb, ru, es) including pluralised "Show N more" forms.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* fix(now-playing-info): switch nested flex-columns to block layout to stop content-dependent drift

Repeated reports of the Tour and Song-info sections rendering at
inconsistent x-positions (sometimes left of the section title,
sometimes centred, sometimes correctly aligned) — varying by artist,
sidebar width, and even whether "Show more" was clicked.

Root cause: nested flex-direction: column containers
(.np-info → .np-info-section → .np-info-tour / .np-info-credits) where
the cross-axis (horizontal) sizing on WebKitGTK occasionally inherits
the intrinsic min-content of the longest child. With one
"Naherholungsgebiet/Freizeitgelände Lago Alfredo"-style venue name
that overflows the sidebar, the parent ul gets pushed past 100% width
and the entire layout drifts. min-width: 0 on every level didn't help
because cross-axis stretch in flex-column ignores it for content-driven
overflow.

Fix: collapse all the section/list containers to display: block. Block
layout is content-agnostic — children always render at 100% parent
width, left-aligned, deterministically. Spacing between siblings now
uses the lobotomy selector (`> * + * { margin-top }`).

Only the tour item itself stays flex (badge ↔ meta horizontal layout),
and that one still has overflow: hidden + flex: 1 1 0 + min-width: 0
on the meta column to truncate venue/place text with ellipsis.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Psychotoxical <dev@psysonic.app>
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/locales/de.ts

@@ -606,6 +606,8 @@ export const deTranslation = {
     discordTemplateLargeText: 'Album-Tooltip (largeText)',
     nowPlayingEnabled: 'Im Livefenster anzeigen',
     nowPlayingEnabledDesc: 'Überträgt den aktuell gespielten Titel an die Livehörer-Ansicht des Servers. Deaktivieren, um keine Wiedergabedaten zu senden.',
+    enableBandsintown: 'Bandsintown-Tourdaten',
+    enableBandsintownDesc: 'Zeigt anstehende Konzerte des aktuellen Künstlers im Info-Tab. Daten werden über die öffentliche Bandsintown-API abgerufen.',
     lyricsServerFirst: 'Server-Lyrics bevorzugen',
     lyricsServerFirstDesc: 'Server-seitige Lyrics (eingebettete Tags, Sidecar-Dateien) vor LRCLIB abfragen. Deaktivieren, um LRCLIB zuerst zu verwenden.',
     enableNeteaselyrics: 'Netease Cloud Music Lyrics',
@@ -1049,6 +1051,30 @@ export const deTranslation = {
     showDuration: 'Dauer anzeigen',
     showRemainingTime: 'Verbleibende Zeit anzeigen',
   },
+  nowPlayingInfo: {
+    tab: 'Info',
+    empty: 'Spiele etwas, um Infos zu sehen',
+    artist: 'Künstler*in',
+    songInfo: 'Songinfos',
+    onTour: 'Auf Tour',
+    noTourEvents: 'Keine bevorstehenden Konzerte',
+    tourLoading: 'Wird geladen…',
+    poweredByBandsintown: 'Tourdaten via Bandsintown',
+    bioReadMore: 'Mehr anzeigen',
+    bioReadLess: 'Weniger anzeigen',
+    showMoreTours_one: '{{count}} weiteres anzeigen',
+    showMoreTours_other: '{{count}} weitere anzeigen',
+    showLessTours: 'Weniger anzeigen',
+    enableBandsintownPrompt: 'Anstehende Konzerte anzeigen?',
+    enableBandsintownPromptDesc: 'Optional. Lädt Tourdaten der aktuellen Künstler*in über die öffentliche Bandsintown-API.',
+    enableBandsintownPrivacy: 'Beim Aktivieren wird der Name der aktuell gespielten Künstler*in an die Bandsintown-API übertragen, um Tourdaten abzurufen. Es werden keine Konto- oder persönlichen Daten gesendet.',
+    enableBandsintownAction: 'Aktivieren',
+    role: {
+      artist: 'Hauptkünstler*in',
+      albumArtist: 'Album-Künstler*in',
+      composer: 'Komponist*in',
+    },
+  },
   songInfo: {
     title: 'Song-Infos',
     songTitle: 'Titel',