Projects tab: create via +, sort by activity/name/count

Declared-but-empty projects persist locally (UserDefaults) until a
note carries the name, at which point the project syncs via notes as
usual. Empty declared projects can be swipe-deleted.

Claude-Session: https://claude.ai/code/session_014esDWi42URLEC6Cj17hGQ3

Notes/Views/Projects/AssignProjectSheet.swift

@@ -17,6 +17,8 @@ struct AssignProjectSheet: View {
     @AppStorage(ProjectsNaming.storageKey) private var namingRaw = ProjectsNaming.projects.rawValue
     private var naming: ProjectsNaming { ProjectsNaming(rawValue: namingRaw) ?? .projects }
 
+    @AppStorage(ProjectsPrefs.declaredKey) private var declaredRaw = ""
+
     var body: some View {
         NavigationStack {
             List {
@@ -79,14 +81,19 @@ struct AssignProjectSheet: View {
         newName.trimmingCharacters(in: .whitespacesAndNewlines)
     }
 
-    /// Distinct project names across live notes, count-sorted like
-    /// `ProjectsView` so the most-used projects surface first.
+    /// Distinct project names across live notes, unioned with names declared
+    /// but not yet used (count 0) so a freshly "+"-created project is
+    /// immediately offered here, count-sorted like `ProjectsView` so the
+    /// most-used projects surface first.
     private var existingProjects: [(project: String, count: Int)] {
         var counts: [String: Int] = [:]
         for note in notes where note.isLive {
             guard let project = note.project else { continue }
             counts[project, default: 0] += 1
         }
+        for name in ProjectsPrefs.decodeDeclared(declaredRaw) where counts[name] == nil {
+            counts[name] = 0
+        }
         return counts
             .map { (project: $0.key, count: $0.value) }
             .sorted { $0.count == $1.count ? $0.project < $1.project : $0.count > $1.count }