Add native macOS SwiftUI app with embedded Python backend

.gitignore

@@ -144,3 +144,7 @@ app/assets/uploads
 # visual studio workspaces
 *.code-workspace
 assets/uploads/*
+
+# Swift Package Manager
+TuttleMac/.build/
+TuttleMac/.swiftpm/

TuttleMac/Makefile

@@ -0,0 +1,13 @@
+PROJECT_ROOT := $(shell cd .. && pwd)
+BINARY := .build/debug/TuttleMac
+
+.PHONY: build run clean
+
+build:
+	swift build
+
+run: build
+	cd $(PROJECT_ROOT) && TuttleMac/$(BINARY)
+
+clean:
+	swift package clean

TuttleMac/Package.swift

@@ -0,0 +1,20 @@
+// swift-tools-version: 5.10
+import PackageDescription
+
+let package = Package(
+    name: "TuttleMac",
+    platforms: [.macOS(.v14)],
+    dependencies: [
+        .package(url: "https://github.com/pvieito/PythonKit.git", branch: "master"),
+    ],
+    targets: [
+        .executableTarget(
+            name: "TuttleMac",
+            dependencies: ["PythonKit"],
+            path: "Sources/TuttleMac",
+            swiftSettings: [
+                .enableExperimentalFeature("StrictConcurrency=minimal"),
+            ]
+        ),
+    ]
+)

TuttleMac/Sources/TuttleMac/ContentView.swift

@@ -0,0 +1,47 @@
+import SwiftUI
+
+struct ContentView: View {
+    @State private var selectedItem: SidebarItem? = .dashboard
+
+    var body: some View {
+        NavigationSplitView {
+            Sidebar(selection: $selectedItem)
+                .frame(minWidth: 180)
+        } detail: {
+            detailView
+                .frame(maxWidth: .infinity, maxHeight: .infinity)
+        }
+    }
+
+    @ViewBuilder
+    private var detailView: some View {
+        switch selectedItem {
+        case .dashboard:
+            DashboardView()
+        case .timeline:
+            TimelineView()
+        case .projects:
+            ProjectsView()
+        case .contracts:
+            ContractsView()
+        case .clients:
+            ClientsView()
+        case .contacts:
+            ContactsView()
+        case .invoicing:
+            InvoicingView()
+        case .none:
+            ContentUnavailableView(
+                "Select an Item",
+                systemImage: "sidebar.left",
+                description: Text("Choose a section from the sidebar.")
+            )
+        default:
+            ContentUnavailableView(
+                selectedItem?.rawValue ?? "Coming Soon",
+                systemImage: selectedItem?.systemImage ?? "hammer",
+                description: Text("This section is not yet implemented.")
+            )
+        }
+    }
+}