Replace manual backend config with auto JWT auth

Device auto-registers on first launch using hardcoded backend URL
and anon key (MarksAuth.swift). 90-day JWT stored in UserDefaults,
refreshed transparently. No settings fields needed — ClaudeService
is always active and non-optional throughout the app.

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

Marks/Views/BookmarksViewModel.swift

@@ -16,23 +16,18 @@ final class BookmarksViewModel {
     var unreadFilter = false
 
     private let api: LinkdingAPI
-    private(set) var claude: ClaudeService?
+    let claude = ClaudeService()
     private var enrichTask: Task<Void, Never>?
     private let cacheFileUrl: URL
 
-    init(api: LinkdingAPI, claude: ClaudeService?, cacheKey: String = "") {
+    init(api: LinkdingAPI, cacheKey: String = "") {
         self.api = api
-        self.claude = claude
         let dir = FileManager.default.urls(for: .applicationSupportDirectory, in: .userDomainMask)[0]
         let safe = cacheKey.replacingOccurrences(of: "/", with: "_").replacingOccurrences(of: ":", with: "_")
         let name = safe.isEmpty ? "bookmarks_cache" : "bookmarks_\(safe)"
         self.cacheFileUrl = dir.appendingPathComponent("\(name).json")
     }
 
-    func updateClaude(_ service: ClaudeService?) {
-        claude = service
-    }
-
     func load(useCache: Bool = true) async {
         if useCache { loadFromCache() }
         isLoading = true
@@ -83,7 +78,7 @@ final class BookmarksViewModel {
     }
 
     func semanticSearch() async {
-        guard let claude, !searchQuery.isEmpty else { return }
+        guard !searchQuery.isEmpty else { return }
         isLoading = true
         do {
             let allResponse = try await api.fetchBookmarks(limit: 200, unread: unreadFilter)
@@ -102,8 +97,7 @@ final class BookmarksViewModel {
         let create = BookmarkCreate(url: url, title: title, tagNames: tags, isArchived: false, unread: false, shared: false)
         let bookmark = try await api.createBookmark(create)
         bookmarks.insert(bookmark, at: 0)
-        print("[AI] addBookmark: saved id=\(bookmark.id) claude=\(claude != nil ? "present" : "nil")")
-        guard let claude else { return }
+        print("[AI] addBookmark: saved id=\(bookmark.id)")
         Task {
             print("[AI] addBookmark: starting enrich for id=\(bookmark.id) url=\(bookmark.url)")
             do {
@@ -159,7 +153,7 @@ final class BookmarksViewModel {
     }
 
     func generateSmartCollections() async {
-        guard let claude, !bookmarks.isEmpty else { return }
+        guard !bookmarks.isEmpty else { return }
         isGeneratingCollections = true
         do {
             let allResponse = try await api.fetchBookmarks(limit: 200)
@@ -171,7 +165,6 @@ final class BookmarksViewModel {
     }
 
     func enrichAll() async {
-        guard let claude else { return }
         let toEnrich = bookmarks.indices.filter { bookmarks[$0].aiSummary == nil }
         guard !toEnrich.isEmpty else { return }
         enrichmentProgress = 0
@@ -191,10 +184,6 @@ final class BookmarksViewModel {
 
     // Silently enrich new bookmarks that lack summaries (background, non-blocking)
     private func startEnrichment() {
-        guard claude != nil else {
-            print("[AI] startEnrichment: skipped (no claude)")
-            return
-        }
         enrichTask?.cancel()
         enrichTask = Task { [weak self] in
             guard let self else { return }
@@ -202,7 +191,7 @@ final class BookmarksViewModel {
             print("[AI] startEnrichment: \(indices.count) bookmarks to enrich")
             for i in indices {
                 guard !Task.isCancelled else { return }
-                guard let claude = await MainActor.run(body: { self.claude }) else { return }
+                let claude = await MainActor.run(body: { self.claude })
                 do {
                     let bm = await MainActor.run { bookmarks[i] }
                     print("[AI] startEnrichment: enriching id=\(bm.id) \(bm.url)")