Stemify iOS 1.1 and WebUI updates, repo restructure into desktop/ios/server/web

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

web/store.js

@@ -15,7 +15,15 @@ export const S = Object.assign({
   keepMix: true,        // carry the mix to the next track when it has no saved mix
   karaoke: false, karaokeMode: "off", softDb: -12,
   sorts: {},            // screen -> sort value
-  stemsOnly: false,
+  stemFilter: "",       // "" | "stems" (only songs with stems) | "nostems"
+  precache: 5,          // Cache Ahead: songs fetched ahead of the one playing (0-50)
+  presetOrder: [],      // preset ids in mixer order: "b:Name" built-in, "c:Name" custom
+  hiddenPresets: [],    // deleted built-ins (deleted custom presets are just gone)
+  customPresets: [],    // [{name, mix}]
+  lockedPreset: "",     // every song starts with this preset
+  acapella: false,      // spell "A Cappella" as "Acapella"
+  bar: { speed: true, mixer: true, lyrics: true, queue: true },  // player bar buttons
+  stations: [],         // web radio: [{id, name, url}]
   theme: "amber", accent: "", css: "",
 }, load(KEY) || {});
 
@@ -28,6 +36,7 @@ if (S.plex) {
   if (!p.env) S.servers.push({ id: "m" + Date.now().toString(36), url: p.url, token: p.token, name: p.name || p.url, sections: S.section ? [{ key: String(S.section), title: "Music", on: true }] : [] });
   delete S.plex; delete S.section;
 }
+if ("stemsOnly" in S) { if (S.stemsOnly) S.stemFilter = "stems"; delete S.stemsOnly; }
 if (S.albumSort) { S.sorts.albums = S.albumSort; delete S.albumSort; }
 
 let timer;
@@ -61,7 +70,8 @@ export function addToPlaylist(p, tracks, mix) {
 }
 
 // ---- offline downloads -----------------------------------------------------------------
-// One record per track: {id, track, entry, fmt, size, peaks, lyrics, blobs: {name: Blob}}.
+// One record per track: {id, track, entry, fmt, size, peaks, lyrics, blobs: {name: Blob}, group}.
+// group is the album or playlist it was downloaded with: {title, href}.
 
 let dbp;
 function db() {