feat: romaji override list — manual kanji→romaji corrections for sort tags

Adds a maintained list in Settings where you can map kanji artist/album/title
strings to their correct romaji reading (e.g. 照井順政 → Terui Yoshimasa).
Overrides are applied last (highest priority) when the edit-metadata modal
opens, so saving the song writes the correct sort tags permanently to the file.

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

src/main.js

@@ -46,6 +46,7 @@ import {
   toggleNotifPanel, deleteNotif, clearNotifs, initNotifBell, _notifNavigate,
   _pickTheme,
   toggleInfoEdit, onInfoArtFile, autofillMusicBrainz, autofillItunes, saveMetadata, deleteSong,
+  addRomajiOverrideUI, removeRomajiOverrideUI,
 } from './ui.js';
 
 // ─── CONNECT ───
@@ -323,6 +324,7 @@ Object.assign(window, {
   editPlUploadCover, editPlCoverSelected, editPlRemoveCover, deletePlaylist, _confirmOk, _confirmCancel,
   toggleMobileSearch, closeMobileSearch, switchSetupTab,
   toggleNotifPanel, deleteNotif, clearNotifs, _notifNavigate, _pickTheme,
+  addRomajiOverrideUI, removeRomajiOverrideUI,
   // App
   doConnect, disconnect,
   // Audiobookshelf