refactor: split views.js and ui.js into focused modules

Extract 3 new files from oversized source files:
- src/components.js (~86 lines): makeCard, makeAlbumCard, makeSongItem,
  makeGlobalTrackItem, mkSection — reusable DOM builders
- src/spotify.js (~187 lines): loadSpotifyImporter, resolveSpotifyLink,
  clearSpotifyPreview, spotifyDlAll, and private render/artwork helpers
- src/nowplaying.js (~255 lines): openNowPlaying, closeNowPlaying,
  syncNowPlaying, switchNpTab, full lyrics engine, renderNpQueue,
  npGoArtist/Album, openNpMenu/closeNpMenu

views.js: 1121 → 864 lines
ui.js:     706 → 462 lines

Update imports in main.js, player.js, views.js accordingly.
Build verified: 15 modules, no errors.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/main.js

@@ -14,11 +14,15 @@ import {
   navigate, _navGoBack, _navLoad, loadHomeData, onLocalSearch, onMobileSearch,
   onGlobalSearch, s_goArtist, s_goAlbum, playerBarGoArtist, playerBarGoAlbum,
   searchSimilarArtist, searchAndPreview, loadItunesAlbum, expandArtistBio,
-  loadRandom, loadSpotifyImporter, resolveSpotifyLink, clearSpotifyPreview, spotifyDlAll,
+  loadRandom,
 } from './views.js';
+import { loadSpotifyImporter, resolveSpotifyLink, clearSpotifyPreview, spotifyDlAll } from './spotify.js';
 import {
   openNowPlaying, closeNowPlaying, switchNpTab, npGoArtist, npGoAlbum,
-  openNpMenu, closeNpMenu, openSettings, closeSettings, saveSettings,
+  openNpMenu, closeNpMenu,
+} from './nowplaying.js';
+import {
+  openSettings, closeSettings, saveSettings,
   checkBackend, openSidebar, closeSidebar, switchNavMode, showCtxMenu,
   openPlModal, closePlModal, addSongsToPlaylist, createAndAddPlaylist,
   createPlaylistPrompt, showSongInfo, closeInfoModal, openDlModal, closeDlModal,