Add Projects: third tab, swipe-to-file, per-project note capture

Notes gain an optional project (schema v4, additive). Projects derive
from note values like tags — no separate entity. Tab naming
(Projects/Categories) is a Settings choice applied across the UI.

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

Notes/Views/Settings/SettingsView.swift

@@ -7,6 +7,8 @@ struct SettingsView: View {
     @Environment(ContextService.self) private var contextService
     @EnvironmentObject private var backupController: BackupController
 
+    @AppStorage(ProjectsNaming.storageKey) private var namingRaw = ProjectsNaming.projects.rawValue
+
     var body: some View {
         NavigationStack {
             Form {
@@ -44,6 +46,15 @@ struct SettingsView: View {
                     }
                 }
 
+                Section("Organization") {
+                    // Renames the Projects tab plus its list headers and swipe/assign UI.
+                    Picker("Group Notes By", selection: $namingRaw) {
+                        ForEach(ProjectsNaming.allCases) { naming in
+                            Text(naming.plural).tag(naming.rawValue)
+                        }
+                    }
+                }
+
                 Section("Context") {
                     ContextSummaryRow(
                         context: contextService.current,