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

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

ios/Stemify/Stems/StemCoverage.swift

@@ -38,14 +38,14 @@ final class StemCoverage: @unchecked Sendable {
         self.settings = settings
         file = dir.appendingPathComponent("library_tracks.json")
         listing = (try? Data(contentsOf: file)).flatMap { try? JSONDecoder().decode(Listing.self, from: $0) }
-        settings.onChange("musicSection") { [weak self] in self?.sectionChanged() }
+        settings.onChange("servers") { [weak self] in self?.sectionChanged() }
         stems.onIndexChange { [weak self] in self?.recompute() }
         sectionChanged()
         recompute()
     }
 
     private func sectionChanged() {
-        let section = settings.musicSection
+        let section = settings.libraryKey
         guard !section.isEmpty else { return }
         if let l = listing, l.section == section, Date().timeIntervalSince1970 - l.at <= Self.staleSeconds { return }
         Task { await refresh() }
@@ -54,7 +54,7 @@ final class StemCoverage: @unchecked Sendable {
     /// Lists every track in the library again (every few hours).
     func refresh() async {
         await lock.run {
-            let section = settings.musicSection
+            let section = settings.libraryKey
             guard !section.isEmpty, plex.signedIn else { return }
             var all: [Slim] = []
             do {
@@ -76,7 +76,7 @@ final class StemCoverage: @unchecked Sendable {
     }
 
     private func recompute() {
-        guard let l = listing, l.section == settings.musicSection, stems.index.size > 0 else { return }
+        guard let l = listing, l.section == settings.libraryKey, stems.index.size > 0 else { return }
         let tracks = l.tracks
         Task.detached { [self] in
             var al: [String: (Int, Int)] = [:]