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/Projects/ProjectsNaming.swift

@@ -0,0 +1,28 @@
+import SwiftUI
+
+/// What the user calls the third tab's grouping. "Projects" by default, but
+/// people organize differently — the label is a Settings choice, applied to
+/// the tab title, list headers, and swipe/assign UI. More options will come;
+/// adding one means adding a case here.
+enum ProjectsNaming: String, CaseIterable, Identifiable {
+    case projects
+    case categories
+
+    static let storageKey = "projectsNaming"
+
+    var id: String { rawValue }
+
+    var plural: String {
+        switch self {
+        case .projects: "Projects"
+        case .categories: "Categories"
+        }
+    }
+
+    var singular: String {
+        switch self {
+        case .projects: "Project"
+        case .categories: "Category"
+        }
+    }
+}