refactor(i18n): split locale files into per-namespace modules (Phase K) (#688)

Each src/locales/<lang>.ts (~1800 LOC) becomes a folder src/locales/<lang>/
with one module per i18n namespace (44 each) plus an index.ts barrel that
reassembles <lang>Translation in the original key order.

Mechanical, script-driven split with a JSON round-trip check: every
locale object is byte-identical to its pre-split form. i18n.ts is
unchanged — './locales/<lang>' now resolves to the folder index.

The per-namespace settings.ts files land ~440-460 LOC; a single i18n
namespace is the natural, non-arbitrary split unit for a flat string
table, so they are intentionally left whole.

src/locales/nl/player.ts

@@ -0,0 +1,56 @@
+export const player = {
+  regionLabel: 'Muziekspeler',
+  openFullscreen: 'Volledig-schermspeler openen',
+  fullscreen: 'Volledig-schermspeler',
+  closeFullscreen: 'Volledig scherm sluiten',
+  closeTooltip: 'Sluiten (Escape)',
+  noTitle: 'Geen titel',
+  stop: 'Stoppen',
+  prev: 'Vorig nummer',
+  play: 'Afspelen',
+  pause: 'Pauzeren',
+  previewActive: 'Voorbeeld speelt af',
+  previewLabel: 'Voorbeeld',
+  delayModalTitle: 'Timer',
+  delayPauseSection: 'Pauzeren na',
+  delayStartSection: 'Starten na',
+  delayPreviewPause: 'Pauze om',
+  delayPreviewStart: 'Start om',
+  delaySchedulePause: 'Pauze plannen',
+  delayScheduleStart: 'Start plannen',
+  delayCancelPause: 'Pauze-timer annuleren',
+  delayCancelStart: 'Start-timer annuleren',
+  delayInactivePause: 'Alleen beschikbaar tijdens afspelen.',
+  delayInactiveStart: 'Alleen in pauze met een geladen nummer of radio.',
+  delayCustomMinutes: 'Aangepaste vertraging (minuten)',
+  delayCustomPlaceholder: 'bijv. 2,5',
+  closeDelayModal: 'Sluiten',
+  delayIn: 'over',
+  delayFmtSec: '{{n}} s',
+  delayFmtMin: '{{n}} min',
+  delayFmtHr: '{{n}} u',
+  delayCancel: 'Annuleren',
+  delayApply: 'Toepassen',
+  next: 'Volgend nummer',
+  repeat: 'Herhalen',
+  repeatOff: 'Uit',
+  repeatAll: 'Alles',
+  repeatOne: 'Één',
+  progress: 'Nummervoortgang',
+  volume: 'Volume',
+  toggleQueue: 'Wachtrij in-/uitschakelen',
+  collapseQueueResize: 'Wachtrij inklappen, breedte wijzigen',
+  moreOptions: 'Meer opties',
+  equalizer: 'Equalizer',
+  miniPlayer: 'Minispeler',
+  lyrics: 'Songtekst',
+  fsLyricsToggle: 'Songtekst in volledig scherm',
+  lyricsLoading: 'Songtekst laden…',
+  lyricsNotFound: 'Geen songtekst gevonden voor dit nummer',
+  lyricsSourceServer: 'Bron: Server',
+  lyricsSourceLrclib: 'Bron: LRCLIB',
+  lyricsSourceNetease: 'Bron: Netease',
+  lyricsSourceLyricsplus: 'Bron: YouLyPlus',
+  showDuration: 'Toon duur',
+  showRemainingTime: 'Toon resterende tijd',
+};